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.
18 playbooks · 509 guides · 96 articles · 13 linked practice labs ·skip to practice
Fast pattern recognition for the production failures engineers see most often.
18 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 CSS Layout Issues: A Systematic Approach to Fixing Broken Layouts
A practical, step-by-step system for diagnosing and fixing CSS layout bugs — from overflow and collapsing margins to flexbox and grid misbehavior. Includes real DevTools workflows and a war story from production.
Debugging Accessibility Violations: A Systematic Approach from Audit to Fix
A practical guide to identifying, triaging, and fixing accessibility violations in web applications, covering automated tools, manual testing techniques, and common pitfalls.
Find the Real Cause of a Slow Page: A Profiling Protocol for Engineers
A practical protocol for profiling web page performance — not a list of metrics, but a repeatable process for finding what actually slows down your users.
Tracking Down Memory Leaks in Browser JavaScript: A Practical Field Guide
Memory leaks in the browser are subtle and hard to reproduce. This guide covers practical techniques to detect, isolate, and fix them using Chrome DevTools, heap snapshots, and allocation timelines.
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.