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.
Documenting Bugs: A Postmortem-Driven Approach That Cut Recurrence by 60%
Most bug write-ups are useless. Here's a structured, postmortem-driven approach that reduced bug recurrence by 60% in our team — with templates and a real incident walkthrough.
Debugging Inside Docker Containers: Tools, Techniques, and a War Story
Practical techniques for debugging inside Docker containers: exec, nsenter, strace, and a real incident that made me rethink debug images.
kubectl logs: Debugging Pods with Logs, Timestamps, and Previous Instances
Beyond `kubectl logs pod-name` — using timestamps, previous instances, and multi-container patterns to diagnose real failures.
Debugging Serverless Functions Locally: A Practical Approach
Local debugging of serverless functions requires different tools and mindset than traditional apps. Here's how I approach it with real examples.
Debugging Terraform and CloudFormation Errors: A Field Guide to the 3 AM Page
Infrastructure-as-code errors are inevitable. Here's how to systematically debug Terraform and CloudFormation failures without losing your mind.
Debugging as Hypothesis Testing: A Mental Model for Systematic Root Cause Analysis
Most debugging is frantic guessing dressed up as experience. Here's a mental model that treats debugging as a scientific process — form hypotheses, design experiments, and isolate root causes systematically.