I took a coworkers existing MyEngine ModPerl2 prototype and refactored it into MyEnginePrototype.pm and MyEngineLogic.pm. Then I reused MyEngineLogic.pm in MyEnginePlackPrototype.pm listed below. (In between I added some tests for MyEngineLogic.pm, yes it is all currently boilerplate scaffolding, that doesn't mean it shouldn't be tested).
All this server has to do is take an incoming request, pass it to a function from the (business)Logic module to get a list of possible responses, then call a helper from the Logic module to pick the winner then finally return the winner to the caller via JSON. Picking the possible responses can be time consuming and will be capped somewhere in the 100-250mS range, none of which is important yet outside of the business logic case. That will get interesting when I look into parallelizing the possible responses code (likely moving from prefork to Coro as the plank server to accomodate this).
Next up I'll benchmark this on a production caliber machine to test for overhead, latency, throughput and max connections. These will provide upper-bound possibilities, since the business logic is mostly empty scaffolding at this point. Testing will be against both Standalone::Prefork and Coro plack server backends.
Running the server via Standalone::Prefork server:
plackup --server Standalone::Prefork --port 8080 MyEnginePlackPrototype.pm
Running the server via Coro server:
plackup --server Coro --port 8080 MyEnginePlackPrototype.pm