From Monolith to Microservices

Microservices are an organizational and operational bet, not a default. Splitting a PHP monolith trades in-process simplicity for network calls, distributed data, and deployment complexity. Done for the wrong reasons it makes everything slower.

This lesson is about the hardest part: drawing service boundaries. Get the seams right and the rest is plumbing; get them wrong and you build a distributed monolith — all the cost, none of the benefit.

Good reasons to split:

• Independent deployability and team ownership.
• Independent scaling of hot subsystems.
• Technology/runtime isolation and fault containment.

Bad reasons: "the code is messy" (refactor the monolith first), or chasing a trend. If two services must always deploy together or share a database table, they are one service wearing two hats.