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.
NextAuth Session Not Persisting: Debugging Silent Token Refresh Failures
A hands-on guide to debugging why NextAuth sessions silently vanish after page navigation, focusing on JWT callback, token refresh, and provider configuration.
Supabase Auth Not Working: Session, Redirect, and JWT Debugging
A hands-on debugging guide for Supabase auth failures—session drops, redirect loops, and JWT validation errors in production.
Passport.js Strategy Not Authenticating: A Diagnostic Walkthrough
Step-by-step guide to debug a Passport.js strategy that silently fails to authenticate, covering serialization, middleware order, and callback pitfalls.
bcrypt.compare() Always Returns False: A Field Guide
Debug why bcrypt.compare() always returns false. Covers salt rounds, encoding mismatches, and truncated hashes with real commands.
Vite Production Build Error: Debugging Crashes, Blank Screens, and Silent Failures
A concise guide to diagnosing and fixing Vite production build errors, including crashes, blank screens, and silent failures.
Vite HMR Not Working: Debugging Stale Modules and Silent Failures
A practical guide to debug Vite Hot Module Replacement when changes don't reflect, including common pitfalls like file watcher limits, dependency caching, and misconfigured optimizations.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Logs, Traces, and the Lies They Tell: Debugging a Stuck Queue in Production
A single stuck queue brought down an entire checkout flow. Here's how we traced the failure across services, what the logs didn't say, and the tools that finally showed the truth.
Pair Debugging: How to Debug Together Without Killing Each Other
Pair debugging sounds great on paper. In practice, it's easy to step on each other's toes, go silent, or fight over the keyboard. Here's how to make it work.
Debugging with AI Tools: What Worked and What Didn't in Production
After a year of using GPT-4, Copilot, and Claude to hunt production bugs, here's what actually helped — and what sent me down dead ends.
How to Debug Legacy Code Without Losing Your Mind
A pragmatic approach to debugging code you didn't write, with techniques for tracing execution, isolating side effects, and making safe edits.
Debugging Feature Flag Rollouts: Tracing the Live-at-5 Incident
A misconfigured feature flag triggered a cascading failure in production. Here's how we traced the root cause and built a better debugging toolkit.
How to Ask for Debugging Help Without Wasting Everyone's Time
Asking for debugging help is a skill. Here's how to provide enough context, show your work, and frame the problem so others can actually help you.