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.
3 playbooks in Data & Storage
Debugging Pagination Bugs
Pagination bugs hide in boundary math, cursor reuse, and new records arriving between pages.
Debugging Transaction Rollback Issues
How to find partial writes when multi-step database workflows fail mid-request.
Debugging Database Consistency Bugs
How to trace query consistency issues across repositories, replicas, and API response contracts.
Structured investigations for the failure modes engineers meet in real systems.
Redis Pub/Sub Subscriber Not Receiving Messages: A Debugging Guide
A practical guide to debugging Redis Pub/Sub when subscribers miss messages. Covers channel mismatches, client disconnections, and message ordering issues.
Redis Cluster Slot Migration Error: Diagnosis and Fix
A practical guide to diagnosing and resolving slot migration errors in Redis Cluster, covering common causes, verification steps, and real-world fixes.
Prisma Migration Drift: Schema Mismatch Between Generated Client and Database
When Prisma's generated client doesn't match the actual database schema, migrations fail or produce inconsistent results. This guide covers detection, root causes, and fixes for schema drift.
How to Find and Fix Prisma N+1 Queries with include and select
A practical guide to debugging N+1 query problems in Prisma when using include and select, with real commands and specific fixes.
TypeORM Relation Eager vs Lazy Loading Errors: Debugging Unexpected Query Behavior
When TypeORM relations load too many or too few rows, the culprit is often a mix of eager and lazy loading settings. This guide covers debugging unexpected query patterns and fixing silent performance issues.
Django ORM N+1 Query Debugging: Finding and Fixing Hidden Database Bloat
A hands-on guide to diagnosing and fixing N+1 query problems in Django ORM, with concrete tools and real server metrics.
Long-form thinking on debugging habits, observability, and the systems around the bug.
How Database Indexes Work: A Debugging Story
A practical guide to understanding database indexes through the lens of debugging a real production outage caused by a missing covering index.
Reading PostgreSQL EXPLAIN ANALYZE Output: A Practical Guide with Real Query Examples
EXPLAIN ANALYZE is the single most important tool for diagnosing slow queries. Here's how to read the output, spot common pitfalls, and fix them with real-world examples.
Debugging Cache Invalidation Failures: A Case Study with Redis and PostgreSQL
Cache invalidation sounds simple — write-through, TTLs, done. But in practice, silent failures hide in race conditions, connection pools, and stale read replicas. Here's a real debugging story with Redis and PostgreSQL that taught me how to find them.
The Real Cost of N+1 Queries: More Than Just Slow Pages
N+1 queries are often dismissed as a minor performance issue, but their real cost goes far beyond slow page loads—think cascading timeouts, database meltdowns, and cloud bills that balloon overnight. Here's what you're actually paying for.