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.
Hunting Down Memory Leaks Caused by Improper WeakMap/WeakSet Usage
A practical guide to diagnosing and fixing memory leaks from WeakMap/WeakSet anti-patterns in production JavaScript applications.
Debugging for-await-of Errors with Async Iterators
A senior engineer's guide to diagnosing and fixing for-await-of errors when consuming async iterators, covering common pitfalls like unhandled rejections, premature termination, and generator misconfiguration.
Debugging Unexpected State Changes from JavaScript Object Mutation
A practical guide to identifying and fixing bugs caused by unintended object mutation in JavaScript, with real-world examples and debugging strategies.
Debugging TypeScript 'satisfies' Operator Errors
A practical guide to diagnosing and resolving type errors when using the TypeScript satisfies operator, including narrowing, excess property checks, and type inference pitfalls.
Debugging TypeScript Readonly Property Violations
How to diagnose and fix readonly property violations in TypeScript, including mutation via methods, aliasing, and array/object nesting.
Debugging JavaScript Proxy Reflect Traps: When Your Proxy Silently Fails
Guide to debugging silent failures in JavaScript Proxy traps when using the Reflect API. Covers missing return values, revoked proxies, and infinite recursion.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Sentry Error Monitoring: A Practical Setup Guide from a Production Outage
A step-by-step setup guide for Sentry error monitoring, covering source maps, release tracking, grouping rules, and alerting — with a real story of a production outage that taught us the hard way.
Reading Prometheus Alert Rules: A Practical Reference for Debugging Firing Alerts
Alert rules look straightforward until you're staring at a firing alert at 3 AM. This post covers the structure, common traps, and how to extract actionable intent from any rule.
Debugging Network Issues with Chrome DevTools: Timing, Waterfalls, and Hidden Columns
A practical guide to diagnosing slow requests, stalled connections, and caching bugs using the Network tab's non-obvious features.
Finding Jank in React Apps with Chrome DevTools Performance Tab
A practical walkthrough of the Performance tab for diagnosing frame drops and long tasks in React apps, with a real debugging story.
Using Breakpoints Effectively: Beyond Step and Continue
Most engineers know F9 to set a breakpoint and F5 to run. But breakpoints have hidden superpowers — conditional, logpoint, hit-count, and data breakpoints — that can cut debugging time in half. Here's how to use them with real examples.
Conditional Breakpoints: When and How to Use Them Beyond the Basics
Conditional breakpoints stop only when a specific condition is true, reducing noise in loops and high-frequency code. Here's how to wield them in Chrome DevTools, VS Code, and IntelliJ, plus a war story about a subtle race condition.