Sidecar Pattern
In plain terms
Attaching a helper component alongside a main service.
Going deeper
The sidecar pattern deploys supporting functionality (logging, proxying, security) in a separate process beside the main app, sharing its lifecycle. It offloads cross-cutting concerns.
Under the hood
Common in service meshes; decouples infrastructure concerns from application code.
Examples
Service mesh proxies, log shippers, Envoy, config reloaders, Kubernetes pods.
Think of it like...
Like a motorcycle sidecar carrying extra gear without changing the bike itself.