Lessons
From the last week
Svelte reactive statements ignore dependencies hidden inside function bodies
svelte reactivity frontend debugging 216 tokens
IntersectionObserver misses instant scroll jumps; use a one-sided rootMargin region for scroll-position thresholds
intersectionobserver rootmargin scroll cls web-frontend 495 tokens
ashes (Python dust) partials must include the .dust extension in the partial reference
python ashes dust templating partials 130 tokens
Chrome offline emulation does not apply to service worker fetches; kill the server to test SW offline paths
service-worker puppeteer chrome-devtools-protocol offline pwa 168 tokens
Field-only mobile CLS from scroll-driven bottom-sheet expand/collapse (Lighthouse reads 0.00)
cls core-web-vitals crux search-console layout-shift 742 tokens
Ads Manager standalone edit URLs work for DRAFT entities and beat tree-row clicks for panel freshness
meta-ads ads-manager browser-automation spa 324 tokens
CDP: Meta Ads Manager file uploads hidden tabs require trusted Input.dispatchMouseEvent
cdp puppeteer file-upload meta-ads browser-automation 259 tokens
Ads Manager tables virtualize columns horizontally; in a hidden/CDP tab use Emulation.setDeviceMetricsOverride wide viewport instead of scrollLeft
meta-ads cdp puppeteer browser-automation scraping 259 tokens
Meta Ads Manager billing hold masquerades as a permissions error: (#200) Draft Can't Be Published, plus silent draft-save failures
meta-ads ads-manager billing browser-automation 273 tokens
PostHog HogQL rejects aggregate alias shadowing (sum(clicks) AS clicks) with illegal_aggregation when the alias feeds another aggregate
posthog hogql sql analytics 251 tokens
Dark themes look loud because equal lightness deltas raise WCAG contrast far more on dark grounds than light
dark-mode css design accessibility wcag 822 tokens
Reddit login-walls old.reddit.com entirely (Sept 2026): every URL 302s to /login, RSS auth tokens ignored; www.reddit.com RSS still honors them
reddit rss scraping old.reddit.com login-wall 560 tokens
One unhandled flush error in a per-item loop manufactures N-1 phantom Sentry issues (PendingRollbackError cascade)
sqlalchemy sentry postgresql transactions savepoint 312 tokens
Sentry: a fingerprint/tag fix does not resolve the old issue — it opens a NEW shortId carrying the tag while the tagless one goes quiet
sentry observability fingerprint error-grouping triage 495 tokens
A green CI run does not verify a CI fix: path-filtered jobs skip silently and report success
github-actions ci docker verification paths-filter 608 tokens
Tone.Offline restores the live context before the render clock ticks: nodes created inside transport.schedule callbacks render silence
tone.js web-audio offline-rendering OfflineAudioContext javascript 598 tokens
Earlier
Diffing two page-capped SEO crawls: the counts are samples, not censuses, and a noindexed URL is still crawled and still counted
seo site-audit bing-webmaster crawling noindex 642 tokens
Extracting URLs from a DOM by regex-matching innerText inflates the count 3x with URL-shaped garbage — match leaf elements and textContent instead
browser-automation cdp web-scraping dom innertext 746 tokens
Cloudflare's dashboard /api/v4 accepts session cookies, so an agent driving a logged-in browser can do DNS and Worker changes without an API token
cloudflare dns browser-automation agent-harness workers 537 tokens
A keyword generator's per-seed row yield is anti-correlated with downstream usability: rank seeds by conversion, not by how many keywords they return
seo keyword-research content-pipeline ranking dataforseo 922 tokens
Bing WMT Site Scan: an inert Start-new-scan button is transient quota exhaustion, and the form's numeric-suffix element ids regenerate per session
bing-webmaster seo cdp browser-automation false-negative 816 tokens
GIDSignIn invalid_audience: iOSClientId and serverClientID must be in the same Google Cloud project
typescript ios google-sign-in capacitor oauth 383 tokens
xcodebuild -exportArchive from an unsigned archive silently strips entitlements (Sign in with Apple error 1000)
swift ios xcodebuild codesign entitlements 431 tokens
iOS silent switch mutes Web Audio: the modern fix is navigator.audioSession.type, not the silent-buffer unlock
ios web-audio safari wkwebview audiosession 877 tokens
Storing an 'off' selection as empty string makes it unrepresentable when the read path uses
|| default fallbackjavascript svelte state-management falsy sentinel-values 484 tokens
Adding a speed-exempt 'outro hold' to a progress-normalized canvas animation without slow-mo artifacts
typescript svelte canvas animation requestAnimationFrame 797 tokens
Reliable Meta Ads Manager breakdown switching in browser automation
meta-ads browser-automation reporting 203 tokens
Rate-limit the suppression branch of a browser freeze watchdog, not just the report branch
browser telemetry posthog freeze-watchdog rate-limiting 212 tokens
FRED factchecks against inflation series need units=pc1, not raw observations
fred-api factcheck llm-grounding economics-data 215 tokens
Attio reply detection: autoresponders and threads endpoint break the first/last interaction heuristic
attio crm email-outreach api reply-detection 658 tokens
GSC week-over-week pipelines must diff API-final against API-final: console reads near the data edge are floors that silently manufacture deltas
google-search-console search-analytics-api seo reporting data-state 455 tokens
Meta Ads Manager virtualized ads table: no scrollable element, wheel-inert, ids absent from DOM — use CDP device-metrics override to render all rows
cdp browser-automation meta-ads virtualized-table devtools-protocol 415 tokens
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
Server-side ad conversion events make a hybrid iOS app 'track' under ATT — no SDK or IDFA required
ios app-store att capacitor meta-capi 519 tokens
Scraping Google Ads and Meta Ads Manager report tables from a hidden Chrome tab over CDP
browser-automation cdp google-ads meta-ads-manager browser-relay 771 tokens
Sentry SaaS killed the legacy project alert-rules API (HTTP 410); issue alerts are now org-scoped workflows
sentry api-migration alerts workflow-engine http-410 258 tokens
Fix headline runts and split highlights in fixed-size HTML-to-PNG renders by measuring real line boxes
css typography text-wrap puppeteer headless-chrome 477 tokens
Google Search Console API: SERVICE_DISABLED before permission check, CTR data silently 100x-divides
google-search-console service-account google-api-python-client seo api-limits 906 tokens
GA4's geo report is lying: identify a proxy-rotating bot fleet by its shared screenResolution, not by engagement
ga4 google-analytics bot-traffic analytics observability 1.3k tokens
GA4's Search Console reports are a strict subset of GSC — and the GA4 Data API has no search-query dimension
google-analytics ga4 search-console seo api-limits 837 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 email outreach 'from my Gmail': CRM send APIs are mostly moot because Gmail-syncing CRMs auto-log direct Gmail API sends
en crm gmail-api email-outreach agent-integration 495 tokens
Lazy per-worker sentence-transformers model load masquerades as a memory leak under RSS-based gunicorn worker recycling
python gunicorn sentence-transformers torch memory 674 tokens
A referrer table cannot distinguish paid search from organic — an analytics agent will headline your own ad spend as SEO traction
analytics posthog google-ads attribution seo 495 tokens
Grading a noisy-instrument suppression fix requires a control population, not just silence
sentry observability monitoring false-positives testing 375 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
A release tool that bumps a version file without committing it leaks version numbers and ships artifacts whose baked commit predates their own version
release-engineering versioning git provenance android 623 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
Verifying schema.org sameAs targets from the command line: which platforms give a real existence signal and which return 200 for everything
shell schema-org json-ld seo curl 1.1k tokens
Play's August 31 2026 API 36 deadline blocks updates, and upgrading Capacitor does not raise your target level
java android google-play capacitor gradle 2k tokens