Presentation
PoC code
Running PoC
Install Tomcat with pre-packaged Camunda engine
Follow installation instructions from here: https://docs.camunda.org/manual/7.5/installation/full/tomcat/pre-packaged/
No need for any manual configuration, just unpack it and start Tomcat.
PoC was tested on https://camunda.org/release/camunda-bpm/tomcat/7.11/camunda-bpm-tomcat-7.11.0.tar.gz.
Build PoC
Maven is needed to build it.
Unzip the PoC package and run mvn clean install from camunda_poc directory.
Run PoC
Copy PoC shared code to Tomcat lib directory: copy camunda_poc/common_code/target/camunda-poc-common-code-1.0-SNAPSHOT.jar to Tomcat lib directory (server/apache-tomcat-9.0.19/lib). 
You need to restart Tomcat after this.
Now you can deploy test applications on running Tomcat without restarts:
- copy camunda_poc/test_app1/target/camunda-poc-test-app1.war to Tomcat webapps directory (server/apache-tomcat-9.0.19/webapps).
- do the same thing for test_app2
Go to Camunda Tasklist application (http://localhost:8080/camunda/app/tasklist), click Start process and run App1_process (or any other for that matter).
Observe Tomcat logs in server/apache-tomcat-9.0.19/logs/catalina.out.
You should get output similar to following in the logs:
>>>>>>>>>> App1LocalDelegateBean invoked >>>>>>>>>> App1LocalDelegateBean invoked >>>>>>>>>> App1LocalComponentBean.beanMethod() invoked >>>>>>>>>> COMMON Delegate Bean invoked >>>>>>>>>> COMMON Delegate Bean invoked >>>>>>>>>> COMMON SpringBean.beanMethod() invoked >>>>>>>>>> App1AnotherDelegateBean invoked >>>>>>>>>> App2LocalDelegateBean invoked >>>>>>>>>> App2LocalDelegateBean invoked >>>>>>>>>> App2LocalComponentBean.beanMethod() invoked >>>>>>>>>> COMMON Delegate Bean invoked >>>>>>>>>> COMMON Delegate Bean invoked >>>>>>>>>> COMMON SpringBean.beanMethod() invoked >>>>>>>>>> App2LocalGroovyClass.someMethod() invoked >>>>>>>>>> CommonGroovyClass.someMethod() invoked