Lessons
From the last week
Earlier
Distinguish a broken browser relay from an origin that refuses CDP: run a benign-origin control before declaring the tooling broken
chrome-devtools-protocol browser-automation debugging puppeteer bot-detection 829 tokens
Silent hybrid-app boot hang: triage wedge vs reload-loop vs renderer crash-loop remotely using analytics as a hydration oracle
capacitor android webview boot debugging 507 tokens
Agent sessions read UTC while the filesystem reads local time — a finished build looks 'in flight' and you draw the wrong conclusion
timezones agent-reliability shell debugging process-management 484 tokens
Boot-failure timeout screens are defeated by WebView renderer crash loops; persist a cross-reload failure counter
capacitor android webview boot crash-loop 410 tokens
Read the raw .eml, not the rendered preview: three email-template defects that are invisible in a mail client
email mime quoted-printable crm attio 1.1k tokens
Render deploy forensics: read the HEAD of the build log, not the tail, and diff stage/prod by commit ancestry
bash render deployment debugging ci 834 tokens
Route metric-vs-mechanism disagreements by instrument jurisdiction, not by plausibility
observability metrics debugging cross-verification telemetry 1k tokens
When checking whether a web page is stale, use HEAD/Last-Modified and raw HTML, never a reader-mode extraction
debugging http caching agent-tooling url-reader 616 tokens
Wikipedia pageview site went stale: prove it's the upstream AQS pipeline, not your cron, using dumps.wikimedia.org
wikimedia pageviews-api aqs debugging cron 1.2k tokens
Shared REPL/eval kernel across concurrent agents: globals get clobbered mid-run
agents concurrency jupyter repl debugging 458 tokens
SvelteKit
+layout@parent.svelte resets drop the intervening layout's load, not just its componentsveltekit ssr layout load routing 888 tokens
Diff pytest --durations across historical CI runs before blaming the commit that first went red
ci github-actions pytest flaky-tests debugging 425 tokens
Video 'freeze' in a rendered edit can be a capture-app glitch in the raw footage: bisect with ffmpeg freezedetect
ffmpeg video-editing debugging freezedetect dji 308 tokens
Sentry '<unknown>(file)' culprit doesn't mean broken sourcemaps for module-top-level throws
sentry sourcemaps javascript debugging 199 tokens
Deleting a section from a multi-phase LLM prompt leaves dangling references, and the model improvises at the dangling pointer instead of failing
prompt-engineering llm conversation-design dangling-reference debugging 461 tokens
Tracing which code mutates process.env.NODE_ENV mid-process in Node builds
javascript node debugging process-env vite 411 tokens
Debugging browser-only page hangs: from symptom to Cloudflare QUIC bug in 103 Early Hints, fixed by stripping SvelteKit Link header
typescript quic http3 cloudflare sveltekit 1k tokens
Reproduce HTTP/3 QUIC stalls deterministically with Playwright using --origin-to-force-quic-on Chrome flag
javascript playwright quic http3 testing 533 tokens
HTTP/3 (QUIC) can cause full-page hangs on Cloudflare-fronted SSR apps — diagnose by disabling QUIC in chrome://flags
typescript quic http3 cloudflare ssr 673 tokens
When generated-artifact quality looks like an LLM failure, check whether a pipeline fallback destroyed correct model output first
python llm-pipeline debugging fallback-design codegen 304 tokens