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.
Spring Security 403 Forbidden Error Debugging
A hands-on guide to diagnosing and fixing 403 Forbidden errors in Spring Security applications, covering hidden causes like annotation misconfigurations and role hierarchy issues.
Spring Boot Application Startup Failure: A Practical Debugging Guide
A concise guide to diagnosing Spring Boot startup failures with concrete commands, logs, and root causes.
Spring JPA LazyInitializationException: Root Causes and Fixes Beyond OpenSessionInView
A practical guide to diagnosing and fixing LazyInitializationException in Spring Data JPA, covering real-world causes like serialization, caching, and transaction boundaries.
Diagnosing and Fixing Java OutOfMemoryError: Java Heap Space
A practical guide to diagnosing Java heap OutOfMemoryError in production, covering non-obvious causes like GC overhead, native memory leaks, and permgen/metaspace issues.
Debugging java.lang.StackOverflowError from Recursion
A practical guide to diagnosing and fixing StackOverflowError caused by unbounded recursion in Java, including thread stack analysis, JVM flags, and code patterns that actually cause this.
Hibernate N+1 Select Problem: Detection, Diagnosis, and Fixes
A hands-on guide to detecting and fixing the Hibernate N+1 query problem with real SQL profiling, lazy loading traps, and JPA fetch strategies.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Profiling SQL Queries: Finding and Fixing the Slow 5%
Profiling SQL queries is more than running EXPLAIN. This guide covers practical techniques to find the slowest queries, interpret execution plans, and fix them — with real examples from PostgreSQL and MySQL.
Debugging Character Encoding Problems: From Gibberish to Unicode
A practical guide to identifying and fixing character encoding problems, from broken UTF-8 to hidden BOM bytes, with real debugging examples.
Debugging Timezone Date Bugs: A Case Study in UTC vs. Local Time
A practical walkthrough of a timestamp bug that broke a billing system, with reproducible code and debugging tactics.
Floating Point Arithmetic Errors: A Debugging Postmortem
How a $0.0000000000000004 error silently corrupted a financial system, and the debugging techniques that caught it.
Why JSON.parse() Throws and How to Catch It: A Field Guide to Parsing Failures
JSON.parse() seems simple until it throws. Here's a practical guide to the most common — and most maddening — parsing failures I've encountered, with exact error messages and fixes.
Debugging Third-Party API Issues: A Systematic Approach
A practical guide to diagnosing and fixing third-party API integration problems, with real-world examples and a step-by-step debugging framework.