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.
Queue consumer not processing messages: how to debug it
Messages pile up in the queue but your consumer does nothing. The consumer might be crashed, stuck, or silently discarding messages.
JWT token invalid after deployment: how to debug it
JWTs work locally and in staging, but after a production deploy every token is rejected. The secret, algorithm, or clock changed.
Node version mismatch in CI: how to debug it
Your code uses a feature from Node 20 but CI runs Node 18. Build fails with a syntax error or missing API. The fix is one line in the CI config.
npm install works locally but fails in CI: how to debug it
npm install completes on your machine but CI throws errors. The issue is usually a clean environment gap: missing native build tools, lockfile drift, or platform-specific binaries.
File upload works locally but fails in production: how to debug it
Your upload endpoint works with local files but returns errors in production. The filesystem, permissions, size limits, or storage backend is different.
API returns 500 only in production: how to debug it
Your API endpoint returns 200 locally but 500 in production. Some code path that never triggers in dev fires in the real environment.
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.