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.
Pulumi State Drift: How Refresh Lies and What to Actually Do
A hard-nosed guide to diagnosing and fixing Pulumi state drift when `pulumi refresh` doesn't behave as expected. Covers real root causes, verification steps, and a war story from production.
Ansible Task Not Idempotent: Changed Every Run
An Ansible task that reports 'changed' on every run is breaking idempotency. This guide covers real-world causes beyond check_mode, from missing diff to transient state in shell commands.
Istio Sidecar Envoy 503: Debugging Upstream Connection Failures
A systematic guide to diagnosing 503 responses from Istio sidecar proxies, covering upstream cluster issues, TLS mismatch, and routing misconfigurations.
Linkerd mTLS Handshake Failures: A Practical Debugging Guide
Linkerd mTLS connections failing? This guide covers diagnosing broken TLS handshakes, certificate mismatches, and policy misconfigurations in Kubernetes.
Debugging SWC Transform Errors: Syntax Errors in Rust-Based JS/TS Transforms
A practical guide to diagnosing and fixing syntax errors when using SWC for JavaScript/TypeScript transforms. Covers common causes like mismatched decorators, unsupported syntax, and misconfigured .swcrc.
Metro Bundler 'Unable to Resolve Module' — Real Debugging & Fix Strategy
A practical guide to debugging Metro Bundler's 'Unable to resolve module' errors in React Native projects, covering cache, aliases, symlinks, and native module misconfigurations.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Sentry Error Monitoring: A Practical Setup Guide from a Production Outage
A step-by-step setup guide for Sentry error monitoring, covering source maps, release tracking, grouping rules, and alerting — with a real story of a production outage that taught us the hard way.
Reading Prometheus Alert Rules: A Practical Reference for Debugging Firing Alerts
Alert rules look straightforward until you're staring at a firing alert at 3 AM. This post covers the structure, common traps, and how to extract actionable intent from any rule.
Debugging Network Issues with Chrome DevTools: Timing, Waterfalls, and Hidden Columns
A practical guide to diagnosing slow requests, stalled connections, and caching bugs using the Network tab's non-obvious features.
Finding Jank in React Apps with Chrome DevTools Performance Tab
A practical walkthrough of the Performance tab for diagnosing frame drops and long tasks in React apps, with a real debugging story.
Using Breakpoints Effectively: Beyond Step and Continue
Most engineers know F9 to set a breakpoint and F5 to run. But breakpoints have hidden superpowers — conditional, logpoint, hit-count, and data breakpoints — that can cut debugging time in half. Here's how to use them with real examples.
Conditional Breakpoints: When and How to Use Them Beyond the Basics
Conditional breakpoints stop only when a specific condition is true, reducing noise in loops and high-frequency code. Here's how to wield them in Chrome DevTools, VS Code, and IntelliJ, plus a war story about a subtle race condition.