Problem domain: Embedded machine vision / Embedded sensor data processing / Autonomous systems.

Process orchestration: Currently very simple. (Python multiprocessing). May change to something more complex in future.

Message versioning: It depends. My configuration management / deployment model means that most of the time backwards compatibility is not required. (The entire system is deployed as a single unit). When messages are persisted, the data recording system files the messages in a configuration management system that knows the system configuration that generated those messages -- so that when they are replayed back -- e.g. to test a new configuration -- the appropriate reading/de-serialization logic can be selected.