platform

Design and maintain shared platform libraries (e.g. packages/shared) that standardize cross-cutting concerns (auth wrappers, config, HTTP/gRPC helpers, typed errors, retry policies, lifecycle hooks). Use when multiple services duplicate boundary logic or need a golden-path primitive; prevents "utils junk drawer" anti-pattern. NOT for single-service code structure (use typescript); NOT for choosing resilience patterns for one call (use resilience).