gRPC

gRPC is Google's open-source RPC framework using HTTP/2 and Protocol Buffers for efficient, type-safe service communication. It excels in microservices architectures where low latency, streaming, and strong typing matter more than REST's simplicity. gRPC supports bidirectional streaming, automatic code generation for 10+ languages, and built-in load balancing. It's the standard for inter-service communication at companies like Netflix, Uber, and Square.