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.
Debugging Production Issues Without a Debugger: Approaches That Work
Attaching an interactive debugger in production is usually impossible. Here’s how I gather signal, reproduce issues, and restore service using other techniques.
Writing Bug Reports That Developers Appreciate
A good bug report is more than a template. Learn which details actually move the needle, and which common 'best practices' waste developer time.
Assert Statements: Where They Help and Where They Hurt
Assert statements are a double-edged sword. Used correctly, they catch bugs early and document invariants. Used carelessly, they can mask failures and create security holes. Here's how to wield them effectively.
Defensive Logging: Patterns for Surviving Production Data Rot
Most logging advice stops at 'log more'. Here's how to log defensively—handling nulls, encoding, PII, and context propagation before they rot your observability pipeline.
Debuggers vs Console.log: Why I Stopped Using Print Statements for Debugging
Print statements are the duct tape of debugging. They work for trivial issues, but for race conditions, async flows, or deep call stacks, a debugger saves hours. Here's what I learned after years of using both.
Treating Bugs as Hypotheses: How the Scientific Method Fixes Debugging
Frustrated by flailing through logs? The scientific method turns debugging into a reproducible process. Here's how to formulate hypotheses, design experiments, and isolate root causes with confidence.