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.
GraphQL Subscription WebSocket Not Receiving Events
A step-by-step debugging guide for when GraphQL subscriptions fail silently over WebSocket—no events, no errors, just silence.
Apollo Client Cache Not Updating After Mutation: How to Force a Normalized Cache Refresh
If Apollo Client returns stale data after a mutation, your normalized cache isn't merging correctly. Here's how to diagnose cache policies, field merge functions, and cache redirects.
Svelte Store Not Updating Component – Reactive Assignment Pitfalls
Learn how to debug a Svelte store that doesn't trigger component re-renders. Covers reactive assignments, store subscriptions, and common Svelte reactivity gotchas.
Debugging Apollo Federation Subgraph Errors: A Field Guide
A practical guide to diagnosing and resolving errors from Apollo Federation subgraphs, including type resolution failures, entity lookup issues, and gateway-subgraph communication problems.
Svelte Reactive Statement Not Re-running After State Change
A deep guide to debugging Svelte reactive statements that fail to re-run: covering dependency tracking pitfalls, stale closures, and assignment traps.
SvelteKit load function errors: root cause analysis and fix patterns
A practical guide to diagnosing and fixing errors in SvelteKit load functions, covering server vs client context, serialization issues, and timing pitfalls.
Long-form thinking on debugging habits, observability, and the systems around the bug.
Logs, Traces, and the Lies They Tell: Debugging a Stuck Queue in Production
A single stuck queue brought down an entire checkout flow. Here's how we traced the failure across services, what the logs didn't say, and the tools that finally showed the truth.
Pair Debugging: How to Debug Together Without Killing Each Other
Pair debugging sounds great on paper. In practice, it's easy to step on each other's toes, go silent, or fight over the keyboard. Here's how to make it work.
Debugging with AI Tools: What Worked and What Didn't in Production
After a year of using GPT-4, Copilot, and Claude to hunt production bugs, here's what actually helped — and what sent me down dead ends.
How to Debug Legacy Code Without Losing Your Mind
A pragmatic approach to debugging code you didn't write, with techniques for tracing execution, isolating side effects, and making safe edits.
Debugging Feature Flag Rollouts: Tracing the Live-at-5 Incident
A misconfigured feature flag triggered a cascading failure in production. Here's how we traced the root cause and built a better debugging toolkit.
How to Ask for Debugging Help Without Wasting Everyone's Time
Asking for debugging help is a skill. Here's how to provide enough context, show your work, and frame the problem so others can actually help you.