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 'this' Being Undefined in JavaScript
A practical guide to diagnosing and fixing 'this' binding errors where this is undefined in JavaScript, covering async callbacks, class methods, and strict mode.
TypeScript Function Overload Resolution: Fixing 'No Matching Signature' Errors
A focused guide to resolving TypeScript's 'No matching signature' error during function overload resolution, covering advanced patterns and real-world debugging tactics.
JavaScript Regex Catastrophic Backtracking Debug Guide
Diagnose and fix catastrophic backtracking in JavaScript regular expressions. Real commands, specific patterns, and a real incident story.
Debugging JavaScript NaN Comparison: Why NaN === NaN is False
A practical guide to understanding why NaN comparisons always return false in JavaScript, with real debugging steps and fixes.
Why Optional Chaining Returns Unexpected Undefined
A debugging guide for when optional chaining (?.) unexpectedly returns undefined instead of the expected value or error.
TypeScript Partial/Omit/Pick Type Errors: When Utility Types Fail at Scale
Debugging type errors with Partial, Omit, and Pick in TypeScript — real causes, concrete fix patterns, and a war story from a production codebase.
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.