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.
18 playbooks · 509 guides · 96 articles · 13 linked practice labs ·skip to practice
Fast pattern recognition for the production failures engineers see most often.
18 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.
WebSocket Reconnect Storm & Thundering Herd Debugging
Diagnose and fix cascading WebSocket reconnection storms triggered by thundering herd patterns in distributed systems.
DNS Caching Stale Records: Why TTL Is Ignored and How to Fix It
A practical guide to debugging cases where DNS resolvers serve stale records past their TTL, covering common causes like resolver caches, stub resolvers, and low TTLs.
Debugging HTTP Keep-Alive Connection Reset by Peer
A practical guide to diagnosing and fixing 'connection reset by peer' errors on HTTP keep-alive connections, covering server, proxy, and network causes.
PostgreSQL Logical Replication Slot Lag: How to Diagnose and Fix WAL Buildup
A concise guide to diagnosing and resolving PostgreSQL logical replication slot lag, including WAL accumulation, consumer failures, and monitoring commands.
PostgreSQL TOAST Table Bloat: Diagnosis and Recovery
A practical guide to identifying, diagnosing, and fixing TOAST table bloat in PostgreSQL, including real commands and war stories.
MongoDB WriteConflict Transaction Retry: A Practical Debugging Guide
Step-by-step debugging guide for MongoDB WriteConflict errors in transactions, covering causes, diagnostics, and fixes.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Debugging Webhook Delivery Failures: What the Logs Don't Tell You
HTTP 200 doesn't mean your webhook was processed. A practical guide to the network and middleware layers that silently drop webhooks.
Debugging HTTP Headers with curl: From Basic Flags to Packet-Level Inspection
A practical guide to inspecting HTTP request and response headers with curl, covering basic flags, debugging tricky issues, and understanding what your headers are really doing.
Debugging WebSocket Real-Time Features: Packet Loss, Reconnect Storms, and Silent Failures
WebSocket debugging goes beyond console.log. I cover packet capture with tcpdump, reconnect backoff strategies, and a war story about a silent failure that took down a production chat feature.
Rest API Design Mistakes That Inject Bugs Into Your System
Most API bugs aren't in the implementation—they're baked into the contract. Here are the design errors I've seen cause the most production incidents.
Blameless Postmortems: How We Fixed Root Causes Without Firing Anyone
A practical guide to running postmortems that focus on systemic failures, not individual mistakes. Includes a real incident breakdown from a production database outage.
Chaos Engineering at 3 AM: When Our Kubernetes Cluster Lost Its DNS
We ran a chaos experiment on our Kubernetes cluster and found a subtle DNS misconfiguration that would have caused a cascading failure. Here's how we did it and what we learned.