Clean-code Go (depth)

On top of the base rules (gofmt, go vet, golangci-lint, table tests).

Errors

• Wrap with context: fmt.Errorf("doing X: %w", err); inspect with errors.Is/errors.As.
• Handle every error where it happens; don't _ = it away. Sentinel errors as package vars when callers must branch.

Interfaces & types

• Define interfaces at the consumer, keep them 1–3 methods. Accept interfaces, return concrete structs.
• Avoid interface{}/any except at true boundaries (encoding). Prefer concrete types and generics where they fit.

Concurrency

• Every goroutine needs a clear stop condition and owner; pass context.Context (first param) and honor cancellation.
• Don't leak goroutines or channels; the launcher is responsible for shutdown. Guard shared state with a mutex or a channel, not both.

Style

• Zero-value-useful structs; constructors only when needed. Early returns; no deep nesting.

Smells

• interface{} threaded through business logic → concrete types/generics.
• A goroutine with no cancellation path → a leak.
• Errors logged and returned at every layer → double logging; wrap and return, log once at the edge.