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.
IndexedDB Data Not Persisting: Silent Writes and Missing Transactions
When IndexedDB writes appear to succeed but data vanishes on reload, the root cause is almost always a mishandled transaction, quota error, or blocked upgrade. This guide exposes the real-world failures behind 'not storing data' and how to trace them.
Web Worker Communication Failures: Why postMessage Stops Working
A deep dive into why postMessage between main thread and web workers silently fails, covering cloning errors, closed ports, and structured clone algorithm limits.
Debugging Ruby Bundler Gem Conflict Errors
A practical guide to diagnosing and resolving gem dependency conflicts in Ruby Bundler, with real commands and war stories.
Rails Database Migration Error: Failed to Add Column Due to Lock Wait Timeout
A practical guide to diagnosing and fixing Rails migration failures caused by lock wait timeouts, schema inconsistencies, and database deadlocks in production.
Detecting and Fixing ActiveRecord N+1 Queries in Rails
A practical guide to identifying, diagnosing, and eliminating N+1 queries in Rails applications using Bullet, rack-mini-profiler, and eager loading.
How to Debug a Failing Sidekiq Job That Keeps Retrying
A practical guide to diagnosing and fixing Sidekiq jobs that fail and retry endlessly—covers real causes, commands, and fixes.
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.