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.
18 playbooks · 509 guides · 96 articles · 13 linked practice labs ·skip to practice
Fast pattern recognition for the production failures engineers see most often.
18 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.
Jest Fake Timers Not Working: A Debugging Guide
A practical guide to debugging when Jest's fake timers (jest.useFakeTimers) don't behave as expected—covering async race conditions, timer scope, and common pitfalls.
Thread Pool Starvation Deadlock: How to Detect, Diagnose, and Fix It
Learn how to identify and resolve thread pool starvation deadlocks where waiting tasks block worker threads, causing cascading failures.
GC Thrashing Causes High CPU — How to Diagnose and Stop It
A practical guide to identifying and resolving garbage collection thrashing that spikes CPU usage in JVM and .NET applications.
Debugging Pandas Merge Producing Duplicate Rows
A targeted guide for diagnosing and fixing unexpected row explosions when merging DataFrames, covering key mismatches, duplicate keys, and index bleed.
Pandas SettingWithCopyWarning: How to Find and Fix the Real Source
A practical guide to eliminating SettingWithCopyWarning in pandas by understanding chain indexing, copy vs. view semantics, and using .loc and .copy() correctly.
RabbitMQ Connection Churn Spiking CPU: Debugging Guide
When clients rapidly open/close connections, RabbitMQ's Erlang VM burns CPU managing channel and process overhead. This guide covers the real causes, from client misconfigurations to rogue heartbeat timeouts.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Logs, Traces, and the Lies They Tell: Debugging a Stuck Queue in Production
A single stuck queue brought down an entire checkout flow. Here's how we traced the failure across services, what the logs didn't say, and the tools that finally showed the truth.
Pair Debugging: How to Debug Together Without Killing Each Other
Pair debugging sounds great on paper. In practice, it's easy to step on each other's toes, go silent, or fight over the keyboard. Here's how to make it work.
Debugging with AI Tools: What Worked and What Didn't in Production
After a year of using GPT-4, Copilot, and Claude to hunt production bugs, here's what actually helped — and what sent me down dead ends.
How to Debug Legacy Code Without Losing Your Mind
A pragmatic approach to debugging code you didn't write, with techniques for tracing execution, isolating side effects, and making safe edits.
Debugging Feature Flag Rollouts: Tracing the Live-at-5 Incident
A misconfigured feature flag triggered a cascading failure in production. Here's how we traced the root cause and built a better debugging toolkit.
How to Ask for Debugging Help Without Wasting Everyone's Time
Asking for debugging help is a skill. Here's how to provide enough context, show your work, and frame the problem so others can actually help you.