gRPC

gRPC is Google's open-source framework for inter-service communication using HTTP/2 and Protocol Buffers (protobuf). Core value: 7-10x faster than REST (binary vs JSON), bidirectional streaming, strong type safety via auto-generated code, and built-in load balancing. Four RPC modes: Unary (request-response like REST), Server streaming (request → stream of responses), Client streaming (stream of requests → response), Bidirectional (both stream). Competes with REST (simplicity, universal support) and WebSockets (real-time, browser support). Netflix, Uber, Square, and Google-scale companies use gRPC internally; it's the standard for microservice-to-microservice communication in Kubernetes environments. Practitioners command $110-140k, Specialists earn $150-190k (+$25-40k premium), Architects commanding $200-260k+. Career path: Protocol Buffers + unary RPCs (L1, weeks 1-2) → streaming + interceptors + error handling (L2, months 1-3) → custom transports, service mesh integration, performance tuning (L3, months 4+). In 2026, gRPC is standard in high-scale infrastructure (Kubernetes, cloud-native microservices); learning it now is investing in infrastructure seniority. Compared to REST: gRPC is harder to learn but enables performance and type safety that REST cannot; adoption growing 20-30% annually in enterprise/cloud contexts. Career optionality: gRPC expertise is portable across all cloud platforms and companies building microservices.