Imagine a single distributed system of more than 550 microservices on 10k servers, and around 600 developers. That’s what Allegro is. Building such a system requires good experience in modularization and architecture. Each of those microservices, however, isn’t necessarily very small, and thus should be decomposed further into modules. Sadly, that’s not always happening, and sometimes the internals of a microservice resemble spaghetti: you can’t tell where it starts and where it ends.