diff --git a/aws/aws-hello-world/.gitignore b/aws/aws-hello-world/.gitignore
new file mode 100644
index 0000000..6c01878
--- /dev/null
+++ b/aws/aws-hello-world/.gitignore
@@ -0,0 +1,32 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
diff --git a/aws/aws-hello-world/Dockerfile b/aws/aws-hello-world/Dockerfile
new file mode 100644
index 0000000..5aa3049
--- /dev/null
+++ b/aws/aws-hello-world/Dockerfile
@@ -0,0 +1,5 @@
+FROM openjdk:8-jdk-alpine
+ARG JAR_FILE=build/libs/*.jar
+COPY ${JAR_FILE} app.jar
+ENTRYPOINT ["java","-jar","/app.jar"]
+EXPOSE 8080
\ No newline at end of file
diff --git a/aws/aws-hello-world/build.gradle b/aws/aws-hello-world/build.gradle
new file mode 100644
index 0000000..7985e86
--- /dev/null
+++ b/aws/aws-hello-world/build.gradle
@@ -0,0 +1,24 @@
+plugins {
+	id 'org.springframework.boot' version '2.2.4.RELEASE'
+	id 'io.spring.dependency-management' version '1.0.9.RELEASE'
+	id 'java'
+}
+
+group = 'io.reflectoring'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = '1.8'
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'org.springframework.boot:spring-boot-starter-web'
+	testImplementation('org.springframework.boot:spring-boot-starter-test') {
+		exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
+	}
+}
+
+test {
+	useJUnitPlatform()
+}
diff --git a/aws/aws-hello-world/gradle/wrapper/gradle-wrapper.jar b/aws/aws-hello-world/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..29953ea
Binary files /dev/null and b/aws/aws-hello-world/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/aws/aws-hello-world/gradle/wrapper/gradle-wrapper.properties b/aws/aws-hello-world/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..9492014
--- /dev/null
+++ b/aws/aws-hello-world/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/aws/aws-hello-world/gradlew b/aws/aws-hello-world/gradlew
new file mode 100755
index 0000000..cccdd3d
--- /dev/null
+++ b/aws/aws-hello-world/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/aws/aws-hello-world/gradlew.bat b/aws/aws-hello-world/gradlew.bat
new file mode 100755
index 0000000..f955316
--- /dev/null
+++ b/aws/aws-hello-world/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/aws/aws-hello-world/settings.gradle b/aws/aws-hello-world/settings.gradle
new file mode 100644
index 0000000..6fefad1
--- /dev/null
+++ b/aws/aws-hello-world/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'aws-hello-world'
diff --git a/aws/aws-hello-world/src/main/java/io/reflectoring/awshelloworld/AwsHelloWorldApplication.java b/aws/aws-hello-world/src/main/java/io/reflectoring/awshelloworld/AwsHelloWorldApplication.java
new file mode 100644
index 0000000..772e434
--- /dev/null
+++ b/aws/aws-hello-world/src/main/java/io/reflectoring/awshelloworld/AwsHelloWorldApplication.java
@@ -0,0 +1,13 @@
+package io.reflectoring.awshelloworld;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class AwsHelloWorldApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(AwsHelloWorldApplication.class, args);
+	}
+
+}
diff --git a/aws/aws-hello-world/src/main/java/io/reflectoring/awshelloworld/HelloWorldController.java b/aws/aws-hello-world/src/main/java/io/reflectoring/awshelloworld/HelloWorldController.java
new file mode 100644
index 0000000..b155b06
--- /dev/null
+++ b/aws/aws-hello-world/src/main/java/io/reflectoring/awshelloworld/HelloWorldController.java
@@ -0,0 +1,14 @@
+package io.reflectoring.awshelloworld;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HelloWorldController {
+
+  @GetMapping("/hello")
+  public String helloWorld(){
+    return "Hello AWS!";
+  }
+
+}
diff --git a/aws/aws-hello-world/src/main/resources/application.properties b/aws/aws-hello-world/src/main/resources/application.properties
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/aws/aws-hello-world/src/main/resources/application.properties
@@ -0,0 +1 @@
+
diff --git a/aws/aws-hello-world/src/test/java/io/reflectoring/awshelloworld/AwsHelloWorldApplicationTests.java b/aws/aws-hello-world/src/test/java/io/reflectoring/awshelloworld/AwsHelloWorldApplicationTests.java
new file mode 100644
index 0000000..41138d1
--- /dev/null
+++ b/aws/aws-hello-world/src/test/java/io/reflectoring/awshelloworld/AwsHelloWorldApplicationTests.java
@@ -0,0 +1,13 @@
+package io.reflectoring.awshelloworld;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class AwsHelloWorldApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}
diff --git a/build-all.sh b/build-all.sh
index 2392e5e..017cba7 100644
--- a/build-all.sh
+++ b/build-all.sh
@@ -4,6 +4,7 @@ MAIN_DIR=$PWD
 
 build_gradle_module() {
   MODULE_PATH=$1
+  echo ""
   echo "+++"
   echo "+++ BUILDING MODULE $MODULE_PATH"
   echo "+++"
@@ -12,15 +13,16 @@ build_gradle_module() {
     ./gradlew clean build --info --stacktrace
     if [ $? -ne 0 ]
     then
+      echo ""
       echo "+++"
       echo "+++ BUILDING MODULE $MODULE_PATH FAILED"
       echo "+++"
       exit 1
     else
+      echo ""
       echo "+++"
       echo "+++ BUILDING MODULE $MODULE_PATH SUCCESSFUL"
       echo "+++"
-      echo ""
     fi
     cd $MAIN_DIR
   }
@@ -29,6 +31,7 @@ build_gradle_module() {
 chmod +x gradlew
 
 build_gradle_module "spring-boot/data-migration/flyway"
+build_gradle_module "reactive"
 build_gradle_module "junit/assumptions"
 build_gradle_module "logging"
 build_gradle_module "pact/pact-feign-consumer"
@@ -49,6 +52,7 @@ build_gradle_module "spring-boot/starter"
 build_gradle_module "spring-boot/startup"
 build_gradle_module "spring-boot/static"
 build_gradle_module "spring-boot/validation"
+build_gradle_module "spring-boot/profiles"
 build_gradle_module "spring-cloud/feign-with-spring-data-rest"
 build_gradle_module "spring-cloud/sleuth-downstream-service"
 build_gradle_module "spring-cloud/sleuth-upstream-service"
@@ -58,6 +62,7 @@ build_gradle_module "spring-data/spring-data-rest-associations"
 build_gradle_module "spring-data/spring-data-rest-springfox"
 build_gradle_module "tools/jacoco"
 
+echo ""
 echo "+++"
 echo "+++ ALL MODULES SUCCESSFUL"
 echo "+++"
\ No newline at end of file
diff --git a/reactive/build.gradle b/reactive/build.gradle
new file mode 100644
index 0000000..9c61496
--- /dev/null
+++ b/reactive/build.gradle
@@ -0,0 +1,25 @@
+buildscript {
+	repositories {
+		mavenCentral()
+	}
+}
+
+apply plugin: 'java'
+
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = 11
+
+repositories {
+	mavenLocal()
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'io.reactivex.rxjava3:rxjava:3.0.0-RC9'
+	testImplementation 'org.junit.jupiter:junit-jupiter-engine:5.0.1'
+	testImplementation 'org.awaitility:awaitility:3.0.0'
+}
+
+test {
+	useJUnitPlatform()
+}
\ No newline at end of file
diff --git a/reactive/gradle/wrapper/gradle-wrapper.jar b/reactive/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..29953ea
Binary files /dev/null and b/reactive/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/reactive/gradle/wrapper/gradle-wrapper.properties b/reactive/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..9492014
--- /dev/null
+++ b/reactive/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/reactive/gradlew b/reactive/gradlew
new file mode 100644
index 0000000..cccdd3d
--- /dev/null
+++ b/reactive/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/reactive/gradlew.bat b/reactive/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/reactive/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/Logger.java b/reactive/src/main/java/io/reflectoring/reactive/batch/Logger.java
new file mode 100644
index 0000000..e39e729
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/Logger.java
@@ -0,0 +1,9 @@
+package io.reflectoring.reactive.batch;
+
+class Logger {
+
+  void log(String string) {
+    System.out.println(String.format("%s %s: %s", System.currentTimeMillis(), Thread.currentThread().getName(), string));
+  }
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/Message.java b/reactive/src/main/java/io/reflectoring/reactive/batch/Message.java
new file mode 100644
index 0000000..a81eddd
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/Message.java
@@ -0,0 +1,19 @@
+package io.reflectoring.reactive.batch;
+
+class Message {
+
+  private final String content;
+
+  Message(String content) {
+    this.content = content;
+  }
+
+  public String getContent() {
+    return content;
+  }
+
+  @Override
+  public String toString() {
+    return content;
+  }
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/MessageBatch.java b/reactive/src/main/java/io/reflectoring/reactive/batch/MessageBatch.java
new file mode 100644
index 0000000..dae86a7
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/MessageBatch.java
@@ -0,0 +1,24 @@
+package io.reflectoring.reactive.batch;
+
+import java.util.Collections;
+import java.util.List;
+
+class MessageBatch {
+
+  private final List<Message> messages;
+
+  MessageBatch(List<Message> messages) {
+    this.messages = messages;
+  }
+
+  public List<Message> getMessages() {
+    return Collections.unmodifiableList(messages);
+  }
+
+  @Override
+  public String toString() {
+    return "MessageBatch{" +
+        "messages=" + messages +
+        '}';
+  }
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/MessageHandler.java b/reactive/src/main/java/io/reflectoring/reactive/batch/MessageHandler.java
new file mode 100644
index 0000000..381e623
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/MessageHandler.java
@@ -0,0 +1,12 @@
+package io.reflectoring.reactive.batch;
+
+interface MessageHandler {
+
+  enum Result {
+    SUCCESS,
+    FAILURE
+  }
+
+  Result handleMessage(Message message);
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/MessageSource.java b/reactive/src/main/java/io/reflectoring/reactive/batch/MessageSource.java
new file mode 100644
index 0000000..750ef72
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/MessageSource.java
@@ -0,0 +1,9 @@
+package io.reflectoring.reactive.batch;
+
+import io.reactivex.rxjava3.core.Flowable;
+
+interface MessageSource {
+
+  Flowable<MessageBatch> getMessageBatches();
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessor.java b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessor.java
new file mode 100644
index 0000000..86a8c9a
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessor.java
@@ -0,0 +1,60 @@
+package io.reflectoring.reactive.batch;
+
+import io.reactivex.rxjava3.core.Flowable;
+import io.reactivex.rxjava3.core.Scheduler;
+import io.reactivex.rxjava3.core.Single;
+import io.reactivex.rxjava3.schedulers.Schedulers;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+public class ReactiveBatchProcessor {
+
+  private final static Logger logger = new Logger();
+
+  private final int threads;
+
+  private final int threadPoolQueueSize;
+
+  private final MessageHandler messageHandler;
+
+  private final MessageSource messageSource;
+
+  ReactiveBatchProcessor(
+      MessageSource messageSource,
+      MessageHandler messageHandler,
+      int threads,
+      int threadPoolQueueSize) {
+    this.messageSource = messageSource;
+    this.threads = threads;
+    this.messageHandler = messageHandler;
+    this.threadPoolQueueSize = threadPoolQueueSize;
+  }
+
+  void start() {
+
+    Scheduler scheduler = threadPoolScheduler(threads, threadPoolQueueSize);
+
+    messageSource.getMessageBatches()
+        .subscribeOn(Schedulers.from(Executors.newSingleThreadExecutor()))
+        .doOnNext(batch -> logger.log(batch.toString()))
+        .flatMap(batch -> Flowable.fromIterable(batch.getMessages()))
+        .flatMapSingle(m -> Single.defer(() -> Single.just(m)
+            .map(messageHandler::handleMessage))
+            .subscribeOn(scheduler))
+        .subscribeWith(new SimpleSubscriber<>(threads, 1));
+  }
+
+  private Scheduler threadPoolScheduler(int poolSize, int queueSize) {
+    return Schedulers.from(new ThreadPoolExecutor(
+        poolSize,
+        poolSize,
+        0L,
+        TimeUnit.SECONDS,
+        new LinkedBlockingDeque<>(queueSize),
+        new WaitForCapacityPolicy()
+    ));
+  }
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV1.java b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV1.java
new file mode 100644
index 0000000..92d430f
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV1.java
@@ -0,0 +1,56 @@
+package io.reflectoring.reactive.batch;
+
+import io.reactivex.rxjava3.core.Flowable;
+import io.reactivex.rxjava3.core.Scheduler;
+import io.reactivex.rxjava3.core.Single;
+import io.reactivex.rxjava3.schedulers.Schedulers;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+public class ReactiveBatchProcessorV1 {
+
+  private final static Logger logger = new Logger();
+
+  private final int threads;
+
+  private final int threadPoolQueueSize;
+
+  private final MessageHandler messageHandler;
+
+  private final MessageSource messageSource;
+
+  public ReactiveBatchProcessorV1(
+      MessageSource messageSource,
+      MessageHandler messageHandler,
+      int threads,
+      int threadPoolQueueSize) {
+    this.messageSource = messageSource;
+    this.threads = threads;
+    this.messageHandler = messageHandler;
+    this.threadPoolQueueSize = threadPoolQueueSize;
+  }
+
+  public void start() {
+    // WARNING: this code doesn't work as expected
+    messageSource.getMessageBatches()
+        .subscribeOn(Schedulers.from(Executors.newSingleThreadExecutor()))
+        .doOnNext(batch -> logger.log(batch.toString()))
+        .flatMap(batch -> Flowable.fromIterable(batch.getMessages()))
+        .flatMapSingle(m -> Single.just(messageHandler.handleMessage(m))
+            .subscribeOn(threadPoolScheduler(threads, threadPoolQueueSize)))
+        .subscribeWith(new SimpleSubscriber<>(threads, 1));
+  }
+
+  private Scheduler threadPoolScheduler(int poolSize, int queueSize) {
+    return Schedulers.from(new ThreadPoolExecutor(
+        poolSize,
+        poolSize,
+        0L,
+        TimeUnit.SECONDS,
+        new LinkedBlockingDeque<>(queueSize)
+    ));
+  }
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV2.java b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV2.java
new file mode 100644
index 0000000..3711864
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV2.java
@@ -0,0 +1,56 @@
+package io.reflectoring.reactive.batch;
+
+import io.reactivex.rxjava3.core.Flowable;
+import io.reactivex.rxjava3.core.Scheduler;
+import io.reactivex.rxjava3.core.Single;
+import io.reactivex.rxjava3.schedulers.Schedulers;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+public class ReactiveBatchProcessorV2 {
+
+  private final static Logger logger = new Logger();
+
+  private final int threads;
+
+  private final int threadPoolQueueSize;
+
+  private final MessageHandler messageHandler;
+
+  private final MessageSource messageSource;
+
+  public ReactiveBatchProcessorV2(
+      MessageSource messageSource,
+      MessageHandler messageHandler,
+      int threads,
+      int threadPoolQueueSize) {
+    this.messageSource = messageSource;
+    this.threads = threads;
+    this.messageHandler = messageHandler;
+    this.threadPoolQueueSize = threadPoolQueueSize;
+  }
+
+  public void start() {
+    // WARNING: this code doesn't work as expected
+    messageSource.getMessageBatches()
+        .subscribeOn(Schedulers.from(Executors.newSingleThreadExecutor()))
+        .doOnNext(batch -> logger.log(batch.toString()))
+        .flatMap(batch -> Flowable.fromIterable(batch.getMessages()))
+        .flatMapSingle(m -> Single.defer(() -> Single.just(messageHandler.handleMessage(m)))
+            .subscribeOn(threadPoolScheduler(threads, threadPoolQueueSize)))
+        .subscribeWith(new SimpleSubscriber<>(threads, 1));
+  }
+
+  private Scheduler threadPoolScheduler(int poolSize, int queueSize) {
+    return Schedulers.from(new ThreadPoolExecutor(
+        poolSize,
+        poolSize,
+        0L,
+        TimeUnit.SECONDS,
+        new LinkedBlockingDeque<>(queueSize)
+    ));
+  }
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV3.java b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV3.java
new file mode 100644
index 0000000..fd02030
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorV3.java
@@ -0,0 +1,58 @@
+package io.reflectoring.reactive.batch;
+
+import io.reactivex.rxjava3.core.Flowable;
+import io.reactivex.rxjava3.core.Scheduler;
+import io.reactivex.rxjava3.core.Single;
+import io.reactivex.rxjava3.schedulers.Schedulers;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingDeque;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+public class ReactiveBatchProcessorV3 {
+
+  private final static Logger logger = new Logger();
+
+  private final int threads;
+
+  private final int threadPoolQueueSize;
+
+  private final MessageHandler messageHandler;
+
+  private final MessageSource messageSource;
+
+  public ReactiveBatchProcessorV3(
+      MessageSource messageSource,
+      MessageHandler messageHandler,
+      int threads,
+      int threadPoolQueueSize) {
+    this.messageSource = messageSource;
+    this.threads = threads;
+    this.messageHandler = messageHandler;
+    this.threadPoolQueueSize = threadPoolQueueSize;
+  }
+
+  public void start() {
+    // WARNING: this code doesn't work as expected
+    Scheduler scheduler = threadPoolScheduler(threads, threadPoolQueueSize);
+
+    messageSource.getMessageBatches()
+        .subscribeOn(Schedulers.from(Executors.newSingleThreadExecutor()))
+        .doOnNext(batch -> logger.log(batch.toString()))
+        .flatMap(batch -> Flowable.fromIterable(batch.getMessages()))
+        .flatMapSingle(m -> Single.defer(() -> Single.just(messageHandler.handleMessage(m)))
+            .subscribeOn(scheduler))
+        .subscribeWith(new SimpleSubscriber<>(threads, 1));
+  }
+
+  private Scheduler threadPoolScheduler(int poolSize, int queueSize) {
+    return Schedulers.from(new ThreadPoolExecutor(
+        poolSize,
+        poolSize,
+        0L,
+        TimeUnit.SECONDS,
+        new LinkedBlockingDeque<>(queueSize)
+    ));
+  }
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/SimpleSubscriber.java b/reactive/src/main/java/io/reflectoring/reactive/batch/SimpleSubscriber.java
new file mode 100644
index 0000000..f260fb8
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/SimpleSubscriber.java
@@ -0,0 +1,42 @@
+package io.reflectoring.reactive.batch;
+
+import org.reactivestreams.Subscriber;
+import org.reactivestreams.Subscription;
+
+class SimpleSubscriber<T> implements Subscriber<T> {
+
+  private final Logger logger = new Logger();
+
+  private final int initialFetchCount;
+  private final int onNextFetchCount;
+
+  private Subscription subscription;
+
+  SimpleSubscriber(int initialFetchCount, int onNextFetchCount) {
+    this.initialFetchCount = initialFetchCount;
+    this.onNextFetchCount = onNextFetchCount;
+  }
+
+  @Override
+  public void onSubscribe(Subscription subscription) {
+    this.subscription = subscription;
+    subscription.request(initialFetchCount);
+    logger.log("subscribed");
+  }
+
+  @Override
+  public void onNext(T message) {
+    subscription.request(onNextFetchCount);
+  }
+
+  @Override
+  public void onError(Throwable t) {
+    logger.log("error");
+  }
+
+  @Override
+  public void onComplete() {
+    logger.log("completed");
+  }
+
+}
diff --git a/reactive/src/main/java/io/reflectoring/reactive/batch/WaitForCapacityPolicy.java b/reactive/src/main/java/io/reflectoring/reactive/batch/WaitForCapacityPolicy.java
new file mode 100644
index 0000000..69bda7b
--- /dev/null
+++ b/reactive/src/main/java/io/reflectoring/reactive/batch/WaitForCapacityPolicy.java
@@ -0,0 +1,18 @@
+package io.reflectoring.reactive.batch;
+
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadPoolExecutor;
+
+class WaitForCapacityPolicy implements RejectedExecutionHandler {
+
+    @Override
+    public void rejectedExecution(Runnable runnable, ThreadPoolExecutor threadPoolExecutor) {
+        try {
+            threadPoolExecutor.getQueue().put(runnable);
+        } catch (InterruptedException e) {
+            throw new RejectedExecutionException(e);
+        }
+    }
+
+}
diff --git a/reactive/src/test/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorTest.java b/reactive/src/test/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorTest.java
new file mode 100644
index 0000000..10f97e3
--- /dev/null
+++ b/reactive/src/test/java/io/reflectoring/reactive/batch/ReactiveBatchProcessorTest.java
@@ -0,0 +1,38 @@
+package io.reflectoring.reactive.batch;
+
+import static org.awaitility.Awaitility.await;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.concurrent.TimeUnit;
+import org.junit.jupiter.api.Test;
+
+class ReactiveBatchProcessorTest {
+
+  @Test
+  void allMessagesAreProcessedOnMultipleThreads() {
+
+    int batches = 10;
+    int batchSize = 3;
+    int threads = 2;
+    int threadPoolQueueSize = 10;
+
+    MessageSource messageSource = new TestMessageSource(batches, batchSize);
+    TestMessageHandler messageHandler = new TestMessageHandler();
+
+    ReactiveBatchProcessor processor = new ReactiveBatchProcessor(
+        messageSource,
+        messageHandler,
+        threads,
+        threadPoolQueueSize);
+
+    processor.start();
+
+    await()
+        .atMost(10, TimeUnit.SECONDS)
+        .pollInterval(1, TimeUnit.SECONDS)
+        .untilAsserted(() -> assertEquals(batches * batchSize, messageHandler.getProcessedMessages()));
+
+    assertEquals(threads, messageHandler.threadNames().size());
+  }
+
+}
diff --git a/reactive/src/test/java/io/reflectoring/reactive/batch/TestMessageHandler.java b/reactive/src/test/java/io/reflectoring/reactive/batch/TestMessageHandler.java
new file mode 100644
index 0000000..2775742
--- /dev/null
+++ b/reactive/src/test/java/io/reflectoring/reactive/batch/TestMessageHandler.java
@@ -0,0 +1,40 @@
+package io.reflectoring.reactive.batch;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+class TestMessageHandler implements MessageHandler {
+
+  private final AtomicInteger processedMessages = new AtomicInteger();
+
+  private final AtomicReference<Set<String>> threadNames = new AtomicReference<>(new HashSet<>());
+
+  private Logger logger = new Logger();
+
+  @Override
+  public Result handleMessage(Message message) {
+    sleep(500);
+    logger.log(String.format("processed message %s", message));
+    threadNames.get().add(Thread.currentThread().getName());
+    processedMessages.addAndGet(1);
+    return Result.SUCCESS;
+  }
+
+  private void sleep(long millis) {
+    try {
+      Thread.sleep(millis);
+    } catch (InterruptedException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  public int getProcessedMessages() {
+    return processedMessages.get();
+  }
+
+  public Set<String> threadNames() {
+    return threadNames.get();
+  }
+}
diff --git a/reactive/src/test/java/io/reflectoring/reactive/batch/TestMessageSource.java b/reactive/src/test/java/io/reflectoring/reactive/batch/TestMessageSource.java
new file mode 100644
index 0000000..f29a41a
--- /dev/null
+++ b/reactive/src/test/java/io/reflectoring/reactive/batch/TestMessageSource.java
@@ -0,0 +1,43 @@
+package io.reflectoring.reactive.batch;
+
+import io.reactivex.rxjava3.core.Flowable;
+import io.reflectoring.reactive.batch.Message;
+import io.reflectoring.reactive.batch.MessageBatch;
+import io.reflectoring.reactive.batch.MessageSource;
+import java.util.ArrayList;
+import java.util.List;
+
+class TestMessageSource implements MessageSource {
+
+  private final int batches;
+
+  private final int batchSize;
+
+  /**
+   * Constructor.
+   *
+   * @param batches   the number of message batches to produce.
+   * @param batchSize the number of messages per batch.
+   */
+  TestMessageSource(int batches, int batchSize) {
+    this.batches = batches;
+    this.batchSize = batchSize;
+  }
+
+  /**
+   * Generates a limited number of {@link MessageBatch}es.
+   */
+  public Flowable<MessageBatch> getMessageBatches() {
+    return Flowable.range(1, batches)
+        .map(this::messageBatch);
+  }
+
+  private MessageBatch messageBatch(int batchNumber) {
+    List<Message> messages = new ArrayList<>();
+    for (int i = 1; i <= batchSize; i++) {
+      messages.add(new Message(String.format("%d-%d", batchNumber, i)));
+    }
+    return new MessageBatch(messages);
+  }
+
+}
diff --git a/spring-boot/profiles/.gitignore b/spring-boot/profiles/.gitignore
new file mode 100644
index 0000000..6c01878
--- /dev/null
+++ b/spring-boot/profiles/.gitignore
@@ -0,0 +1,32 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
diff --git a/spring-boot/profiles/README.md b/spring-boot/profiles/README.md
new file mode 100644
index 0000000..cb9caf7
--- /dev/null
+++ b/spring-boot/profiles/README.md
@@ -0,0 +1,5 @@
+# Spring Boot Profiles Examples
+ 
+## Related Blog Articles
+
+* [One-Stop Guide to Spring Profiles](https://reflectoring.io/spring-boot-profiles/)
\ No newline at end of file
diff --git a/spring-boot/profiles/build.gradle b/spring-boot/profiles/build.gradle
new file mode 100644
index 0000000..7d8c61e
--- /dev/null
+++ b/spring-boot/profiles/build.gradle
@@ -0,0 +1,24 @@
+plugins {
+	id 'org.springframework.boot' version '2.2.2.RELEASE'
+	id 'io.spring.dependency-management' version '1.0.8.RELEASE'
+	id 'java'
+}
+
+group = 'io.reflectoring'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = '11'
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation 'org.springframework.boot:spring-boot-starter'
+	testImplementation('org.springframework.boot:spring-boot-starter-test') {
+		exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
+	}
+}
+
+test {
+	useJUnitPlatform()
+}
diff --git a/spring-boot/profiles/gradle/wrapper/gradle-wrapper.jar b/spring-boot/profiles/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..29953ea
Binary files /dev/null and b/spring-boot/profiles/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/spring-boot/profiles/gradle/wrapper/gradle-wrapper.properties b/spring-boot/profiles/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..9492014
--- /dev/null
+++ b/spring-boot/profiles/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.0.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/spring-boot/profiles/gradlew b/spring-boot/profiles/gradlew
new file mode 100644
index 0000000..cccdd3d
--- /dev/null
+++ b/spring-boot/profiles/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/spring-boot/profiles/gradlew.bat b/spring-boot/profiles/gradlew.bat
new file mode 100644
index 0000000..f955316
--- /dev/null
+++ b/spring-boot/profiles/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/spring-boot/profiles/settings.gradle b/spring-boot/profiles/settings.gradle
new file mode 100644
index 0000000..19868c9
--- /dev/null
+++ b/spring-boot/profiles/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'profiles'
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BarBean.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BarBean.java
new file mode 100644
index 0000000..838cd56
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BarBean.java
@@ -0,0 +1,18 @@
+package io.reflectoring.profiles;
+
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Component;
+
+class BarBean {
+
+  private static final Logger logger = LoggerFactory.getLogger(BarBean.class);
+
+  @PostConstruct
+  void postConstruct(){
+    logger.info("loaded BarBean!");
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BaseConfiguration.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BaseConfiguration.java
new file mode 100644
index 0000000..e9e6f1d
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BaseConfiguration.java
@@ -0,0 +1,36 @@
+package io.reflectoring.profiles;
+
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+@Configuration
+class BaseConfiguration {
+
+  private static final Logger logger = LoggerFactory.getLogger(BaseConfiguration.class);
+
+  @PostConstruct
+  void postConstruct() {
+    logger.info("loaded BaseConfiguration!");
+  }
+
+  @Bean
+  @Profile("bar")
+  BarBean barBean() {
+    return new BarBean();
+  }
+
+  @Profile("local")
+  OutputPort mockedOutputPort(){
+    return new MockedOutputPort();
+  }
+
+  @Profile("!local")
+  OutputPort realOutputPort(){
+    return new RealOutputPort();
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BazBean.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BazBean.java
new file mode 100644
index 0000000..0f0bb15
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/BazBean.java
@@ -0,0 +1,20 @@
+package io.reflectoring.profiles;
+
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Component;
+
+@Component
+@Profile("baz")
+class BazBean {
+
+  private static final Logger logger = LoggerFactory.getLogger(BazBean.class);
+
+  @PostConstruct
+  void postConstruct(){
+    logger.info("loaded BazBean!");
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/DefaultBean.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/DefaultBean.java
new file mode 100644
index 0000000..03a5b03
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/DefaultBean.java
@@ -0,0 +1,20 @@
+package io.reflectoring.profiles;
+
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Component;
+
+@Component
+@Profile("default")
+class DefaultBean {
+
+  private static final Logger logger = LoggerFactory.getLogger(DefaultBean.class);
+
+  @PostConstruct
+  void postConstruct(){
+    logger.info("loaded DefaultBean!");
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/FooBean.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/FooBean.java
new file mode 100644
index 0000000..3bcf97c
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/FooBean.java
@@ -0,0 +1,22 @@
+package io.reflectoring.profiles;
+
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.context.annotation.Profile;
+import org.springframework.stereotype.Component;
+
+@Component
+@Profile("foo")
+@ConditionalOnProperty(value = "mock.enabled", havingValue = "false", matchIfMissing = true)
+class FooBean {
+
+  private static final Logger logger = LoggerFactory.getLogger(FooBean.class);
+
+  @PostConstruct
+  void postConstruct(){
+    logger.info("loaded FooBean!");
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/FooConfiguration.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/FooConfiguration.java
new file mode 100644
index 0000000..8aae647
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/FooConfiguration.java
@@ -0,0 +1,20 @@
+package io.reflectoring.profiles;
+
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+@Configuration
+@Profile("foo")
+public class FooConfiguration {
+
+  private static final Logger logger = LoggerFactory.getLogger(FooConfiguration.class);
+
+  @PostConstruct
+  void postConstruct(){
+    logger.info("loaded FooConfiguration!");
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/HelloBean.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/HelloBean.java
new file mode 100644
index 0000000..f12e191
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/HelloBean.java
@@ -0,0 +1,17 @@
+package io.reflectoring.profiles;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+@Component
+class HelloBean {
+
+  private static final Logger logger = LoggerFactory.getLogger(HelloBean.class);
+
+  HelloBean(@Value("${helloMessage}") String helloMessage) {
+    logger.info(helloMessage);
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/MasterConfiguration.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/MasterConfiguration.java
new file mode 100644
index 0000000..f22fdd4
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/MasterConfiguration.java
@@ -0,0 +1,10 @@
+package io.reflectoring.profiles;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+@Configuration
+@Profile("master")
+public class MasterConfiguration {
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/MockedOutputPort.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/MockedOutputPort.java
new file mode 100644
index 0000000..d2aebc8
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/MockedOutputPort.java
@@ -0,0 +1,5 @@
+package io.reflectoring.profiles;
+
+public class MockedOutputPort implements OutputPort {
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/OutputPort.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/OutputPort.java
new file mode 100644
index 0000000..79e7530
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/OutputPort.java
@@ -0,0 +1,5 @@
+package io.reflectoring.profiles;
+
+public interface OutputPort {
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/ProfileScannerBean.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/ProfileScannerBean.java
new file mode 100644
index 0000000..016ebea
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/ProfileScannerBean.java
@@ -0,0 +1,28 @@
+package io.reflectoring.profiles;
+
+import java.util.Arrays;
+import javax.annotation.PostConstruct;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.env.Environment;
+import org.springframework.stereotype.Component;
+
+@Component
+class ProfileScannerBean {
+
+  private static final Logger logger = LoggerFactory.getLogger(ProfileScannerBean.class);
+
+  private Environment environment;
+
+  ProfileScannerBean(Environment environment) {
+    this.environment = environment;
+  }
+
+  @PostConstruct
+  void postConstruct(){
+    String[] activeProfiles = environment.getActiveProfiles();
+    logger.info("the following profiles are active: {}", Arrays.toString(activeProfiles));
+  }
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/ProfilesApplication.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/ProfilesApplication.java
new file mode 100644
index 0000000..05827cb
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/ProfilesApplication.java
@@ -0,0 +1,15 @@
+package io.reflectoring.profiles;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ProfilesApplication {
+
+	public static void main(String[] args) {
+		SpringApplication application = new SpringApplication(ProfilesApplication.class);
+		application.setAdditionalProfiles("baz");
+		application.run(args);
+	}
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/RealOutputPort.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/RealOutputPort.java
new file mode 100644
index 0000000..8a5e284
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/RealOutputPort.java
@@ -0,0 +1,5 @@
+package io.reflectoring.profiles;
+
+public class RealOutputPort implements OutputPort {
+
+}
diff --git a/spring-boot/profiles/src/main/java/io/reflectoring/profiles/WorkerConfiguration.java b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/WorkerConfiguration.java
new file mode 100644
index 0000000..0c41ba9
--- /dev/null
+++ b/spring-boot/profiles/src/main/java/io/reflectoring/profiles/WorkerConfiguration.java
@@ -0,0 +1,10 @@
+package io.reflectoring.profiles;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+
+@Configuration
+@Profile("worker")
+public class WorkerConfiguration {
+
+}
diff --git a/spring-boot/profiles/src/main/resources/application-foo.yml b/spring-boot/profiles/src/main/resources/application-foo.yml
new file mode 100644
index 0000000..abec02a
--- /dev/null
+++ b/spring-boot/profiles/src/main/resources/application-foo.yml
@@ -0,0 +1 @@
+helloMessage: "Hello Foo!"
\ No newline at end of file
diff --git a/spring-boot/profiles/src/main/resources/application-local.yml b/spring-boot/profiles/src/main/resources/application-local.yml
new file mode 100644
index 0000000..b7adf63
--- /dev/null
+++ b/spring-boot/profiles/src/main/resources/application-local.yml
@@ -0,0 +1,4 @@
+helloMessage: "Hello Local!"
+
+database-url: "localhost:1234"
+mock.enabled: true
diff --git a/spring-boot/profiles/src/main/resources/application-prod.yml b/spring-boot/profiles/src/main/resources/application-prod.yml
new file mode 100644
index 0000000..5e3f538
--- /dev/null
+++ b/spring-boot/profiles/src/main/resources/application-prod.yml
@@ -0,0 +1,4 @@
+helloMessage: "Hello Prod!"
+
+database-url: "path-to-the-real-db:1234"
+mock.enabled: false
diff --git a/spring-boot/profiles/src/main/resources/application.yml b/spring-boot/profiles/src/main/resources/application.yml
new file mode 100644
index 0000000..3aa2e3a
--- /dev/null
+++ b/spring-boot/profiles/src/main/resources/application.yml
@@ -0,0 +1,5 @@
+spring.profiles.active: foo
+helloMessage: "Hello Default!"
+
+database-url: "INVALID!"
+mock.enabled: false
\ No newline at end of file
diff --git a/spring-boot/profiles/src/test/java/io/reflectoring/profiles/FooBarProfileTest.java b/spring-boot/profiles/src/test/java/io/reflectoring/profiles/FooBarProfileTest.java
new file mode 100644
index 0000000..8bc9331
--- /dev/null
+++ b/spring-boot/profiles/src/test/java/io/reflectoring/profiles/FooBarProfileTest.java
@@ -0,0 +1,15 @@
+package io.reflectoring.profiles;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+@SpringBootTest
+@ActiveProfiles({"foo", "bar"})
+class FooBarProfileTest {
+
+	@Test
+	void test() {
+	}
+
+}
diff --git a/spring-boot/profiles/src/test/java/io/reflectoring/profiles/FooProfileTest.java b/spring-boot/profiles/src/test/java/io/reflectoring/profiles/FooProfileTest.java
new file mode 100644
index 0000000..54dfdba
--- /dev/null
+++ b/spring-boot/profiles/src/test/java/io/reflectoring/profiles/FooProfileTest.java
@@ -0,0 +1,15 @@
+package io.reflectoring.profiles;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+@SpringBootTest
+@ActiveProfiles({"foo"})
+class FooProfileTest {
+
+	@Test
+	void test() {
+	}
+
+}