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.
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.