We've been following this modular monolith approach as well (for 3 years now), bounded contexts and all, but our architectural end goal is still "mostly microse

We've been following this modular monolith approach as well (for 3 years now), bounded contexts and all, but our architectural end goal is still "mostly microservices". Maybe it's specific to PHP and the frameworks we use (what the modulith is written in) but the startup time of the monolith is just unacceptable for our processing rates (for every request the framework has to be reinitialized again, with all the 9000 services via DI and what not). Microservices tend to be much more lightweight (you don't even need DI frameworks), and monolith also encourages synchronous calls (calling a bounded context's API in memory is so simple) which has been detrimental to our performance and stability, because microservices, at least in our architecture, encourage event-based communication which is more scalable, and allows clean retries on failure etc. But again, your mileage may vary, maybe it's specific to our tools.