Your gRPC Protobuf Types Don't Belong in Your Domain Layer

Book: Hexagonal Architecture in Go Also by me: Thinking in Go (2-book series) — Complete Guide to Go Programming + Hexagonal Architecture in Go My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub You run protoc . It generates Go structs. They have fields that match your domain. So you pass them straight into your service layer. Three months later, someone adds an optional field to the .proto file. The CI is green.