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.
How to Read Error Messages: A Debugging Protocol
Most engineers skim error messages and miss the signal. Here's a repeatable protocol for extracting maximum information from stack traces, log lines, and crash dumps — with a real incident walkthrough.
When to Escalate a Bug: A Decision Framework for Junior and Mid-Level Engineers
A practical framework for junior and mid-level engineers to decide when to escalate a bug, with real-world examples and criteria beyond time spent.
Debugging vs. Firefighting: Why Treating Production Incidents as Debugging Sessions Fails
When production goes down, your brain wants to debug. That instinct costs you hours. Here's why firefighting requires a fundamentally different approach, and the specific process I use to switch modes.
Writing an Incident Runbook That Actually Gets Used in Production
A runbook isn't a document—it's a tool. Here's how to write one that reduces MTTR and doesn't embarrass you during the next PagerDuty alert.
Debugging a production incident with your boss on Slack: staying rational when everything is on fire
A personal account of debugging a cascading Redis failure while the VP of Engineering watched, and the mental models that kept the fix from turning into a rollback.
Reading Distributed Traces to Find Latency: A Field Guide
Tracing tools generate a firehose of data. Here's how to filter the signal from the noise and actually find the root cause of high latency.