Idiomatic Go patterns, best practices, and conventions for building robust, efficient, and maintainable Go applications. Use when writing or reviewing Go code and idiomatic structure or conventions are in question.

Go Development Patterns Idiomatic Go patterns and best practices for building robust, efficient, and maintainable applications. When to Activate Writing new Go code Reviewing Go code Refactoring existing Go code Designing Go packages/modules Core Principles 1. Simplicity and Clarity Go favors simplicity over cleverness. Code should be obvious and easy to read. 2. Make the Zero Value Useful Design types so their zero value is immediately usable without initialization. 3. Accept Interfaces, Return Structs Functions should accept interface parameters and return concrete types. Error Handling Patterns Error Wrapping with Context Custom Error Types Error Checking with errors.Is and errors.As Never Ignore Errors Concurrency Patterns Worker Pool Context for Cancellation and Timeouts Graceful Shutdown errgroup for Coordinated Goroutines Avoiding Goroutine Leaks Interface Design Small, Focused Interfaces Define Interfaces Where They're Used Optional Behavior with Type Assertions Package Organization Standard Project Layout Package Naming Avoid Package Level State Struct Design Functional Options Pattern Embedding for Composition Memory and Performance Preallocate Slices When Size is Known Use sync.Pool for Frequent Allocations Avoid String Concatenation in Loops Go Tooling Integration Essential Commands Recommended Linter Configuration (.golangci.yml) Quick Reference: Go Idioms Idiom Description Accept interfaces, return structs Functions accept interface params, return concrete types Errors are values Treat errors as first class values, not exceptions Don't communicate by sharing memory Use channels for coordination between goroutines Make the zero value useful Types should work without explicit initialization A little copying is better than a little dependency Avoid unnecessary external dependencies Clear is better than clever Prioritize readability over cleverness gofmt is no one's favorite but everyone's friend Always format with gofmt/goimports Return early Handle errors first, keep happy path unindented Anti Patterns to Avoid Remember : Go code should be boring in the best way predictable, consistent, and easy to understand. When in doubt, keep it simple.

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