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.
JavaScript Long Task Blocking Main Thread: Diagnosis and Fixes
A practical guide to identifying and fixing JavaScript long tasks that block the browser's main thread, causing jank and poor user experience.
Debugging High Interaction to Next Paint (INP) Scores
A practical guide to diagnosing and fixing poor Interaction to Next Paint (INP) scores, covering event handler delays, rendering bottlenecks, and real-user monitoring.
Service Worker Serving Stale Content: A Debugging Guide
Diagnose and fix service workers that refuse to update cached assets, leaving users stuck on old JavaScript bundles or stale API responses.
Debugging JavaScript Garbage Collection Pauses That Kill Responsiveness
Learn how to identify and fix long GC pauses in Node.js and browser JavaScript using Chrome DevTools, Node --trace-gc, and heap snapshots.
OpenTelemetry Traces Not Appearing: Debugging Missing Spans in Production
A debugging guide for when OpenTelemetry traces are not appearing in your observability backend. Covers common and non-obvious causes like sampling misconfiguration, exporter timeouts, and context propagation failures.
Node.js CPU Profiling: Fixing a Stuck Event Loop in Production
A practical guide to diagnosing Node.js CPU spikes using flame graphs, perf, and async hooks. Includes a real incident where a JSON serialization loop blocked the event loop for 12 seconds.
Long-form thinking on debugging habits, observability, and the systems around the bug.
The Debugging Mindset: A Systematic Method for Finding Root Causes
A repeatable, hypothesis-driven approach to debugging that works for intermittent failures, performance regressions, and production incidents.
Analyzing a Core Dump: What to Do When Your Process Goes Silent
A core dump is your process's last scream. Here's how to make it talk.
Timeouts Every Engineer Gets Wrong (and How to Fix Them)
Most timeout bugs aren't logic errors — they're configuration failures. Here's how to stop treating timeouts as magic numbers and start engineering them deliberately.
Backpressure in Streaming Systems: When Your Pipeline Fights Back
Backpressure is the system's way of saying 'slow down.' Ignore it and you get OOM crashes, silent data loss, or cascading failures. Here's how to design for it.
Finding Memory Leaks Step by Step: A Systematic Approach
Memory leaks are the silent killers of long-running services. Here's a repeatable process to hunt them down, from heap dumps to production monitoring.