MSA is a decision about which criterion to use to decompose the system. Domain boundary, data ownership, scale pattern, failure isolation — the chosen criterion creates the service boundaries, and those boundaries decide communication and data in turn.
ES and CQRS address how a system’s source of truth is shaped and how its views are separated from it. Adoption cost spreads across the system, so I lean toward adopting only when the value can be stated explicitly.
Distributed transactions are about how a single ACID transaction decomposes across services and how its pieces are reassembled. The roles and trade-offs of 2PC, Saga (Choreography vs Orchestration), and Outbox.
The difference between splitting code by technical layers (horizontal) and by features or domains (vertical). Trade-offs and selection criteria for each approach.
Layered architecture separates code into horizontal layers by technical responsibility. A summary of the four-layer structure, dependency direction rules, and how DIP decouples layers.
Core concepts of Hexagonal Architecture and its idiomatic implementation in Go using implicit interfaces and package structure for dependency direction control.