Sidecar

1. The Pattern

Deploy a small helper process beside every service instance. It runs on the same machine and talks to the service over localhost. The helper does the networking work: TLS, retries, timeouts, metrics, and tracing. The service does only its own job.

The module now moves inward to east-west traffic, which consists of direct calls among internal services. These calls require the same consistent supporting behavior as public requests.

Service communication needs mutual TLS, meaning encrypted connections in which both participants prove their identity