gRPC
A fast binary RPC framework over HTTP/2 — how backend microservices call each other when JSON-over-REST is too slow or too loose.
In one line
gRPC is remote procedure calls with a contract: you define services and messages in a
.proto file, the toolchain generates typed client/server code, and calls travel as
compact binary (Protocol Buffers) over HTTP/2 with built-in streaming.
How it works
The .proto contract is the single source of truth — every language gets generated
stubs, so a Python analytics service can call a Go ingestion service with compile-time
type safety. HTTP/2 gives multiplexing and four call shapes: unary, server-streaming,
client-streaming, bidirectional. Deadlines, retries and load-balancing are first-class.
The trade-off: binary protocols are not browser-native (grpc-web exists) and are harder
to debug with curl than JSON.
Where it shows up in digital health
Internal seams of health platforms: ingestion pipelines, ML inference services, device-gateway to cloud links — anywhere high-volume structured traffic flows between your own services. The external, standards-facing edge stays FHIR/REST; gRPC is for inside the walls.