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 · 96 articles · 13 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.
TLS Handshake Failure: Connection Reset Debugging Guide
A practical guide for diagnosing and fixing TLS handshake failures that manifest as connection resets, covering packet-level analysis, cipher mismatches, and server-side issues.
OpenTelemetry Metrics Not Exporting: A Field Guide
A direct, actionable guide for debugging OpenTelemetry metrics that fail to export. Covers collector configuration, SDK timing, and common silent failures.
Astro Component Hydration Not Working: Debugging Missing Client-Side Interactivity
A debugging guide for Astro components that fail to hydrate: symptoms, root causes, diagnosis steps, and fixes for missing client-side interactivity.
Debugging TypeScript Module Augmentation When It Silently Fails
A direct guide to diagnosing why your TypeScript module augmentation doesn't take effect, covering ambient module declarations, import side effects, and module resolution quirks.
Postgres Sequence Gaps in SERIAL ID: Why They Happen and How to Stop Panicking
A no-fluff guide to understanding why Postgres serial IDs have gaps, how to identify the cause, and when to actually worry.
CSS Modules Class Not Found: Why Your Imported Styles Object Returns Undefined
When a CSS Modules class import resolves to undefined at runtime, the root cause is almost always a misconfiguration in your build pipeline. This guide walks through the five real reasons it happens and how to fix each one.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Profiling SQL Queries: Finding and Fixing the Slow 5%
Profiling SQL queries is more than running EXPLAIN. This guide covers practical techniques to find the slowest queries, interpret execution plans, and fix them — with real examples from PostgreSQL and MySQL.
Debugging Character Encoding Problems: From Gibberish to Unicode
A practical guide to identifying and fixing character encoding problems, from broken UTF-8 to hidden BOM bytes, with real debugging examples.
Debugging Timezone Date Bugs: A Case Study in UTC vs. Local Time
A practical walkthrough of a timestamp bug that broke a billing system, with reproducible code and debugging tactics.
Floating Point Arithmetic Errors: A Debugging Postmortem
How a $0.0000000000000004 error silently corrupted a financial system, and the debugging techniques that caught it.
Why JSON.parse() Throws and How to Catch It: A Field Guide to Parsing Failures
JSON.parse() seems simple until it throws. Here's a practical guide to the most common — and most maddening — parsing failures I've encountered, with exact error messages and fixes.
Debugging Third-Party API Issues: A Systematic Approach
A practical guide to diagnosing and fixing third-party API integration problems, with real-world examples and a step-by-step debugging framework.