Practical tips: what a reverse proxy is (educational) and how to use it in infrastructure

Practical tips: what a reverse proxy is (educational) and how to use it in infrastructure

A reverse proxy sits between clients and one or more backend servers and accepts incoming requests on behalf of those servers, acting as a single point of entry for a service or application, which simplifies network topologies and centralises concerns such as security and routing.

At its simplest a reverse proxy receives HTTP or TCP connections from clients and forwards them to appropriate origin servers, while returning responses to the client, which means the client often does not know which backend served the request, and the proxy can add, remove or modify headers and manage TLS for all backends.

Common use cases you should know include load balancing to distribute work across servers, TLS termination to offload encryption, caching to reduce backend load, compression to save bandwidth and request routing to direct different paths or hosts to distinct services, which together improve resilience and operational control.

When placing a reverse proxy in your architecture, prefer it as the public gateway for a service so you centralise access control and observability, run at least two instances for high availability with a failover or DNS-based approach, and ensure health checks are configured so unhealthy backends are automatically removed from the pool.

Configure the proxy conservatively to begin with and iterate based on telemetry, set sensible timeouts and buffer sizes to avoid head-of-line blocking, preserve the client IP with X-Forwarded-For or the PROXY protocol so logs and rate limiting work correctly, and avoid leaking internal details by sanitising headers and error messages on responses.

Security practises to apply include terminating TLS at the proxy while using mutual TLS to authenticate backends where appropriate, placing management interfaces on a separate network or loopback with strict ACLs, enabling rate limiting to mitigate abusive traffic, and pairing the proxy with a web application firewall where you need defence in depth for web applications.

• Cache static assets aggressively and set short or validation-based caching for dynamic content to balance freshness with efficiency.
• Use brotli or gzip compression for textual content but avoid compressing already-compressed media to save CPU cycles.
• Offload session affinity only when necessary; prefer stateless backends or shared session stores to avoid sticky session complexity.
• Monitor latency and error budgets from the proxy outward so you can detect backend issues quickly and fail over gracefully.

In operational terms keep configuration in code and deploy changes with a repeatable pipeline so rollbacks are straightforward, centralise logging and metrics at the proxy layer for a clear view of incoming traffic patterns, and consult related posts on the site if you want wider context on infrastructure design, such as the collection labelled Infrastructure. For more builds and experiments, visit my main RC projects page.