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.
Debugging Cypress Tests Inside an iFrame: The Cross-Origin Trap
A practical debugging guide for when Cypress tests fail inside iframes—covering cross-origin restrictions, timing issues, and element access.
Cypress intercept stub not intercepting requests — debugging guide
A debugging guide for when cy.intercept() stubs silently fail to match or intercept requests, covering URL patterns, method mismatches, timing, and aliasing traps.
React Testing Library fireEvent Not Triggering: Silent Failures and Real Fixes
When React Testing Library's fireEvent doesn't trigger, it's usually due to stale closures, wrong event type, or async state updates. This guide covers real causes and fixes.
MSW Request Not Intercepted: Why Your Handler Isn't Catching the Call
A practical guide to debugging why MSW (Mock Service Worker) handlers fail to intercept requests, covering worker registration, URL mismatches, and lifecycle issues.
GraphQL Resolver Not Being Called: How to Diagnose and Fix
A practical guide to diagnosing why a GraphQL resolver isn't executing, covering schema mismatches, null bubbling, authentication filters, and resolver registration issues.
GraphQL Variable Type Mismatch Error Debugging
How to diagnose and fix GraphQL variable type mismatch errors caused by null handling, enum coercion, and schema mismatches.
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.