Nginx

Nginx (pronounced "engine-x") handles a substantial portion of the internet's traffic. It started as a high-performance web server but evolved into a Swiss Army knife: reverse proxy, load balancer, HTTP cache, and more. If your architecture involves serving web traffic, Nginx is probably part of it. As a web server, Nginx excels at serving static files efficiently. The event-driven architecture handles thousands of concurrent connections without spawning processes for each one. Memory usage stays low even under heavy load. For static sites, single-page apps, or serving assets, Nginx is faster and lighter than most alternatives. Reverse proxying is where Nginx typically lives in production. It sits in front of application servers—Node.js, Python, Ruby—handling SSL termination, compression, and connection management. Your application focuses on business logic while Nginx handles the HTTP complexity. Load balancing distributes traffic across multiple backends. You configure upstream server pools, choose balancing algorithms, and Nginx routes requests. Health checks detect failed backends and remove them from rotation. For basic load balancing, no additional tools needed. The configuration language is declarative and relatively straightforward. Server blocks define virtual hosts, location blocks define URL handling. Most common setups map to readable configuration. Complex routing, rewrites, and conditional logic are possible but require deeper knowledge. The open-source version handles most needs. NGINX Plus adds enterprise features like active health checks, session persistence, and dynamic configuration. Most users start with open source and only evaluate Plus if specific features are required. For anyone deploying web applications, understanding Nginx basics is valuable. It's infrastructure that's everywhere.