Simple but not 100% foolproof, you can mutate your source code and verify the changes propagate.

Note the endpoint does a DYNAMIC lookup of source code. So you can kinda reassure yourself the endpoint is executing dynamic code just by providing your own source code.

It might be more obvious the runtime does nothing much if you see the runtime https://github.com/endpointservices/serverlesscells

The clever bits that actually implement services are all in the notebooks.