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.
Stale lock bug: how locks that are never refreshed cause outages
A lock is acquired, the operation succeeds, but the lock is never released or refreshed. Other processes wait until the lock TTL expires, causing delays or outages.
Tenant cache leak: how to debug cross-tenant data exposure through caching
A user from Tenant A sees data from Tenant B because the cache key does not include the tenant identifier. The cache is leaking data across tenants.
Observability missing logs: how to debug gaps in logging and monitoring
A critical error happened in production but there are no logs for it. The log level is too high, logs are dropped under load, or the log pipeline has a silent failure.
Log says success but the user still fails: how to debug misleading logs
Your application logs 'Operation completed successfully' but the user sees an error or gets no result. The log is lying — it is logging intent, not outcome.
Background job stuck: how to debug jobs that never complete
A background job enters the queue, a worker picks it up, and then nothing. The job never completes, never fails, and never retries. It is stuck in limbo.
Race condition in payment flow: how to debug concurrent payment issues
Two requests hit the payment endpoint at the same time. Both check the balance, both see enough funds, and both deduct. The user is charged twice.
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.