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.
Debugging Webhook Delivery Failures: What the Logs Don't Tell You
HTTP 200 doesn't mean your webhook was processed. A practical guide to the network and middleware layers that silently drop webhooks.
Debugging HTTP Headers with curl: From Basic Flags to Packet-Level Inspection
A practical guide to inspecting HTTP request and response headers with curl, covering basic flags, debugging tricky issues, and understanding what your headers are really doing.
Debugging WebSocket Real-Time Features: Packet Loss, Reconnect Storms, and Silent Failures
WebSocket debugging goes beyond console.log. I cover packet capture with tcpdump, reconnect backoff strategies, and a war story about a silent failure that took down a production chat feature.
Rest API Design Mistakes That Inject Bugs Into Your System
Most API bugs aren't in the implementation—they're baked into the contract. Here are the design errors I've seen cause the most production incidents.
Blameless Postmortems: How We Fixed Root Causes Without Firing Anyone
A practical guide to running postmortems that focus on systemic failures, not individual mistakes. Includes a real incident breakdown from a production database outage.
Chaos Engineering at 3 AM: When Our Kubernetes Cluster Lost Its DNS
We ran a chaos experiment on our Kubernetes cluster and found a subtle DNS misconfiguration that would have caused a cascading failure. Here's how we did it and what we learned.