Modern applications are more distributed and complex than ever, making it harder to pinpoint why performance slows down or where users are dropping off. Slow screen loads, delayed network requests, and hidden backend bottlenecks can quickly degrade user experience and drive customers away. Without the right visibility, teams are left reacting to complaints instead of proactively improving performance. This ebook breaks down how to build an effective performance monitoring strategy that delivers actionable insight across your stack. You’ll explore key concepts such as Real User Monitoring (RUM), server-side monitoring, OpenTelemetry, and distributed tracing, and learn how to use them together to uncover issues faster. It also explains how a developer-first approach helps teams turn performance data into meaningful improvements that protect user experience and business outcomes.