Software Architecture: The Hard Parts - Modern Trade-Off Analyses for Distributed Architectures

A book about the hardest decisions in distributed systems - the ones that have no "best practices", only trade-offs. The authors show how to approach such decisions systematically: from how granular services should be to who owns the data and how to keep it consistent. Everything is explained through a single running story: a team gradually breaking a legacy monolith apart into a distributed system.

It is best read once you are already familiar with microservices: the book does not explain the basics, but teaches you to weigh options where there is no single right answer.