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.
How to Debug a Regression: A Practical Walkthrough
A practical, step-by-step guide to finding and fixing regression bugs, with real-world examples and concrete commands you can run today.
The Cost of Not Reproducing Bugs: Why Local Debugging Saves Hours
Skipping local reproduction leads to wasted hours, broken deploys, and frustrated teams. Here's why it's non-negotiable and how to do it right.
Debugging an Unfamiliar Codebase: A Systematic Approach
A repeatable process for debugging code you didn't write — with specific techniques, tooling choices, and a war story from a production outage at 2 AM.
5 Questions to Ask Yourself Before Filing a Bug Report
A senior engineer's pre-flight checklist for bug reports — forged in the fire of a production incident that turned a 5-minute fix into a 3-hour hunt.
Binary Search for Bugs: Cutting Down Bisection Time with git bisect run
Automating git bisect with a script turns days of manual hunting into minutes. Here's how to build a reliable bisection harness for your codebase.
Reading a Call Stack: What Each Frame Actually Tells You
A call stack shows you the path your code took to crash. But most developers only look at the top frame. Here’s how to read the whole thing — including async traces, native frames, and minified code.