Buglyst Blog
Learn to debug under pressure.
Playbooks for fast pattern recognition, guides for the full investigation, and articles for the engineering judgment around the edges.
17 playbooks · 509 guides · 95 articles · 12 linked practice labs ·skip to practice
Fast pattern recognition for the production failures engineers see most often.
1 playbook in Frontend & Web
Structured investigations for the failure modes engineers meet in real systems.
React setState Called but State Not Updating: Real Debugging Steps
React state not updating after setState? Pinpoint hidden causes—like stale closures, async timing, or skipped re-renders—using targeted debugging tactics.
React.memo Fails to Prevent Re-render: Deep Props, Functions, and Traps
Debug React.memo not working: identify why supposedly memoized components still re-render, including deep prop equality, unstable functions, and context pitfalls.
Diagnosing 404s from Next.js API Routes That Should Exist
When your Next.js API route responds with a 404 despite existing, dig past simple typos. This guide covers real fixes, pitfalls, and non-obvious causes.
Next.js Middleware Not Executing on Expected Routes
Investigate why your Next.js middleware isn't firing as expected. This guide goes beyond basics and addresses subtle config, routing, and deployment issues.
Environment Variable Undefined at Runtime in Next.js Projects
Why and how Next.js environment variables end up undefined during runtime, including hidden build pitfalls. Step-by-step debugging for real production issues.
Diagnosing ‘React Hook Called Conditionally’ in Function Components
A hands-on guide to resolving errors from calling React hooks inside conditional blocks. Covers root causes, real-world mistakes, and validation steps.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Why Your 60fps Animation Stutters: A Deep Dive Into the Browser Event Loop
The event loop isn't just about callbacks. It's about when and in what order the browser processes tasks, microtasks, and rendering. Here's what actually happens between frames.
Remote Debugging Mobile Devices at Scale: What Works and What Doesn't
Setting up remote debugging for iOS and Android devices involves more than just enabling Developer Mode. Here's what I've learned from debugging over 500 devices in production.