Debugging Next.js applications in production can be tricky. Developers often struggle to pinpoint the source of issues or understand how those issues affect users. Sentry offers a solution by providing tools to monitor application behavior, assess performance, and troubleshoot problems as they arise. The article outlines how to integrate Sentry into Next.js applications effectively. Key steps include configuring Sentry and ensuring source maps are set up and verified. This setup is vital for tracking errors accurately. The article also addresses specific challenges, such as debugging hydration errors, issues with Error Boundaries, and complications related to React Server Components (RSC). For those working with Incremental Static Regeneration (ISR), it highlights how to manage related errors to maintain app stability. Performance troubleshooting is another focus. The article describes how to use logs, tracing, and metrics to investigate performance issues. It emphasizes the importance of early detection of regressions in performance and errors through a tool called Seer, which can help developers address potential problems proactively.