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.
MySQL 'Too Many Connections' Error — Root Cause Diagnosis & Fix
Step-by-step debugging guide for MySQL's 'Too many connections' error — covers hidden causes like connection pooling leaks, thread stack exhaustion, and how to fix without bouncing the server.
MongoDB Aggregation Pipeline Returns Wrong Results: A Debugging Guide
A practical guide to debugging incorrect results from MongoDB aggregation pipelines, covering stage order, data types, and memory limits.
Why MongoDB Queries Miss the Index — and How to Catch It
A practical guide for diagnosing why MongoDB ignores an index, covering query shape, sort/select mismatches, and silent index suppression.
MongoDB Change Stream Not Receiving Events: Diagnostic Walkthrough
A direct, actionable guide for diagnosing and fixing change streams that silently stop delivering events. Covers replica set priming, oplog sizing, stale cursors, and network splits.
MongoDB Document Size Limit (16MB) Debugging
A practical guide to diagnosing and fixing the 'document exceeds maximum size' error in MongoDB, covering gridfs, oversized arrays, and subdocument bloat.
Redis Memory Eviction Debugging: Why Your Hot Keys Keep Disappearing
A hands-on guide to diagnosing why Redis evicts keys under memory pressure, with real commands and production scenarios.
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.