Why a HIPAA-compliant edge system chose gRPC over Unix sockets instead of HTTP

A developer building PhotonicOps, an offline telemetry and hardware-triage system for clinical silicon photonic biosensors, faced a key architectural decision on a single-host Apple Silicon edge deployment. The system ingests optical resonance data at 10,000 samples per second and must pass batches of sensor frames from a Go ingestion engine to a Python DSP pipeline without any cloud API calls, due to HIPAA compliance requirements. The core transport question was whether to use plain HTTP on a loopback port or gRPC over a Unix socket for that one internal process-to-process hop. Three concrete, code-level reasons drove the choice away from HTTP: native client-streaming support in gRPC, a strict sub-10ms per-frame processing budget, and the overhead costs of reconstructing similar functionality manually over HTTP/1.1. The article focuses on the reasoning behind the losing option rather than simply advocating for gRPC, framing the tradeoff analysis as the transferable insight for engineers facing similar decisions.