Logging with Winston and Morgan
Logging is not console.log — it is a structured, levelled, persistent record of everything significant that happens in your application. In production, logs are your primary tool for diagnosing incidents, understanding user behaviour, and auditing security events. Winston is the most widely used Node.js logging library; Morgan is Express's HTTP request logging middleware. Together they cover both application-level events (Winston) and request-level events (Morgan).
Analogy🏏Cricket
Think of it like cricket: Every professional cricket match generates three types of records simultaneously: the official scorecard (structured match data), the ball-by-ball commentary log (request-level events), and the umpire's decision log (application-level events and errors). After a controversial match, the ICC reviews all three records together to understand exactly what happened. Winston is the umpire's decision log and ball-by-ball commentary log — it records what your application decided and why. Morgan is the match scorecard — it records every delivery (HTTP request) with its outcome. Both are essential because you need different granularities of information when investigating different types of incidents.