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.
17 playbooks
Debugging Env Var Issues
A concise checklist for incidents where local works but CI, staging, or production changes behavior.
Debugging Cache Stampedes
How to recognize and contain request spikes when cached data expires.
Debugging CORS Origin Bugs
A practical way to inspect origin parsing, credentials, and header behavior.
Debugging Retry Bugs
Retry issues often hide the first failure and create duplicate work.
Debugging Timezone Bugs
Time bugs usually live at day boundaries, DST changes, and unit conversions.
Debugging Pagination Bugs
Pagination bugs hide in boundary math, cursor reuse, and new records arriving between pages.
Structured investigations for the failure modes engineers meet in real systems.
Express-Session Not Saving Between Requests: The Real Causes
A debugging guide for when express-session fails to persist session data across HTTP requests in Node.js applications.
Node.js Heap Snapshot Analysis: Finding the Leak That Survived GC
A practical guide to analyzing Node.js heap snapshots to find memory leaks that survive garbage collection. Covers snapshot comparison, retaining paths, and hidden class instances.
Node.js Module Resolution: Why 'Cannot Find Module' Keeps Happening
A practical debugging guide for Node.js 'cannot find module' errors, covering real-world causes like path aliases, hoisting edge cases, and missing native addons.
Express req.body Undefined: Body-Parser Not Working
Debug why Express `req.body` returns undefined even after installing body-parser. Covers middleware order, missing Content-Type, and URL encoding issues.
Debug Node.js child_process.spawn() Failures
A direct guide to diagnosing and fixing ENOENT, EPIPE, and silent failures in child_process.spawn().
Node.js Worker Threads Messages Not Received: Debugging Communication Failures
A practical guide to debugging messages that never arrive between Node.js main thread and worker threads, covering postMessage timing, cloning errors, and port exhaustion.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Five Debugging Habits That Separate Seniors from Juniors
It's not tools. It's not years of experience. It's five repeatable habits that senior engineers do reflexively and juniors haven't built yet.
Why Your Production Logs Are Lying to You
Logs tell you what the code reported. They almost never tell you what actually happened. Here is the gap, and how to close it.
The Real Cost of Console.log Debugging (and What to Use Instead)
Every engineer reaches for console.log. Most do not think about what it costs — in time, in performance, or in production readiness. Here is the honest accounting.
Interpreting Stack Traces: Practical Steps for Faster Debugging
Stack traces can be dense, but reading them fluently accelerates triage and root cause analysis. This article explains how to extract actionable information, with real-world context.
Efficient Debugging with git bisect: Going Beyond Binary Search
This article explains how to incorporate git bisect into your debugging workflow, focusing on practical execution, automation, and common edge cases.
Applying Rubber Duck Debugging to Complex Engineering Problems
Rubber duck debugging isn’t just a quirky solo exercise. I’ll show how explaining code out loud surfaces misunderstandings and reduces wasted team cycles.