Uber-go/zap is a high-performance, structured logging library for Go. It provides two primary logger types: the zero-allocation, reflection-free Logger for hot-path usage and the ergonomic SugaredLogger for printf-style logging. The library emphasizes minimal allocations through object pooling, lazy field evaluation, and efficient encoders (JSON and console). It includes advanced features like sampling, dynamic level adjustment via AtomicLevel, hook systems for extensibility, and integration with testing, gRPC, and standard library. The architecture is modular, separating public API (zap), core implementation (zapcore), testing utilities (zaptest), and experimental features (exp).