Go in Action, Second Edition has been substantially rewritten for modern Go, fully updated with the language, tooling, and development practices Go programmers use today. Completely updated for modern Go, with examples requiring Go 1.25 or later An entirely new chapter on generics, including type parameters, constraints, generic functions and data structures Error handling, including sentinel errors, custom error types, and error wrapping Testing workflows including unit testing, TDD, benchmarking, profiling, and Go’s built-in fuzz testing. Updated concurrency coverage built around a practical concurrent RSS reader Modern structured logging with log/slog alongside Go’s standard library Go modules and workspaces, replacing the GOPATH-era dependency-management material from the first edition and showing how to organize larger, multimodule Go projects New production-oriented architecture examples, including interfaces, dependency inversion, domain-driven design, and hexagonal architecture Two brand-new AI-focused appendices covering LLM-powered summarization and retrieval-augmented generation New and rewritten examples throughout designed around real applications About the reader Professional developers proficient in at least one object-oriented language who want to build high-performance backend systems, cloud native applications, or AI-integrated pipelines. About the author Joel Holmes is a software developer building cloud native applications at EasyPost. Andy Walker is a Google Developer Expert in Go and Gophercon staff member. A coauthor of the first edition of Go in Action, William Kennedy is a founding member of GoBridge.