E2E Testing of BPMN Processes

A BPMN process can run for weeks, call dozens of external systems, and spawn subprocesses. Unit tests verify the logic of each step in isolation, while BPMN tests with mocked delegates check the route, but with stubs instead of real code. Bugs at the seams between processes and subprocesses, timers and external events are invisible to both approaches. 

This talk presents an E2E framework for Camunda that runs the entire path from a Kafka event to the final state with a real engine and real BPMN routing, yet zero external dependency. It covers three key techniques: synchronising with the asynchronous engine via polling the REST API, fast-forwarding timers without touching system clocks, and isolating tests for parallel execution in a shared infrastructure. 

We will also explain how we integrated these tests into the development workflow, where we still stumble, and what compromises we have accepted.