Building API Timer Middleware in Go

Every millisecond counts when delivering modern web services, but you cannot optimize what you do not measure. Understanding how to track and log the execution time of your HTTP handlers is a foundational skill for maintaining high-performance Go applications. In this comprehensive, text-only course, you will transition from writing basic endpoints to building robust, reusable middleware that automatically tracks API latency. You will master the inner workings of HTTP request flows in Go and learn how to intercept them to gather precise performance metrics. What you'll learn: - Understand the core concepts of HTTP middleware and the Go handler execution flow. - Measure request execution duration accurately using Go's standard time package. - Implement custom middleware to intercept incoming requests and log response times in milliseconds. - Apply modern structured logging using Go's standard slog package for clean, production-ready metrics. - Test middleware behavior and performance using the native net/http/httptest package. Starting with basic HTTP handler structures and terminology, the course guides you step-by-step through intercepting requests, wrapping handlers, and calculating elapsed time. You will practice by analyzing clean, idiomatic Go code and reinforcing your learning through practical written exercises. This course is designed for beginner Go developers who want to deepen their backend skills and build more observable applications. No prior experience with middleware is required, though a basic understanding of Go syntax and HTTP concepts is recommended. Start reading today to master Go middleware and gain clear visibility into your application's performance.