📰 Dev.to · Anand Rathnas

3,059 lines of Cloudflare Worker tests using Vitest and vi.stubGlobal, no miniflare required. Here's why lightweight unit tests catch the bugs that matter.

14 lines fixed a maddening flaky test. Auth0 SPA SDK writes tokens to localStorage after handleRedirectCallback(), but Playwright snapshots state before the wri

We deleted 10,000 lines of Terraform and added 1,637 lines of Playwright E2E tests. Here are the 5 things that took longer than writing the actual tests.

A brand clicks 'Accept' on a bid, but the bid stays in SUBMITTED state. The root cause: notification failures were rolling back the entire transaction.

Two endpoints, two opposite behaviors for inactive campaigns — and both are correct. Here's why pixel tracking returns 200 while postbacks return 400.

235 lines of changes to add FTC disclosure acknowledgment as a server-side gate. Small diff, legally critical. Here's why a checkbox isn't enough.

How we modeled bid negotiations as a state machine with display priority, bid templates, and a security fix for a timing-attack oracle. 1,782 lines of tests.

How we built a full affiliate marketplace with Stripe Connect integration where jo4 never holds or moves a single dollar. 14 database tables, 27 services, 81 te

Our mobile app hammered the server every 30 seconds for notifications. We ripped it out and built direct FCM + APNs push. Here's every step.

A 5-line config that plays a sound notification when Claude Code finishes a task or needs your input. Tiny hack, massive quality-of-life upgrade.

How we built a tile-merging game with level-ups, marshmallow animations, and an AI autoplay that uses expectimax search with corner-lock strategy.

Need a custom printable calendar? Our free PDF generator has year, month, and weekly views with day filtering. No signup, no ads, works offline.

Referral marketing tools start at $29/mo and don't include link tracking. We already had the link infrastructure. So we built Referral Kit.

You already have Stripe working perfectly. Then Apple says your mobile app needs IAP. Here's how I integrated RevenueCat with a Spring Boot backend without losi

You deleted the URL. Redis says it's gone. But users click it and still get redirected. The culprit: stale Cloudflare CDN cache that nobody told to purge.

Fire Meta Pixel on every short link click without touching your destination site. Perfect for affiliate marketers and advertisers.

Our mobile CI/CD went from 'push to Play Store' to 'push to both stores simultaneously' with parallel EAS builds. Here's the workflow.

We added AdSense to every page. Conversions dropped. Here's why utility pages and ads don't mix, and where ads actually make sense.

Auth0's free tier includes 25,000 MAU. Their paid Essentials plan starts at 500 MAU. Yes, you read that right. Here's how to think about Auth0 pricing as a star

A 405 from bot scanners, a filter ordering misfire, and a race condition in user creation. All in one commit. Here's what went wrong.

Our OAuth scope parsing worked in tests but failed in production. A comma vs a space broke Pipedream. Here's the fix.

Our dev.to sync tool republished unchanged articles daily. The root cause: comparing updatedAt against published_at instead of edited_at.

Our URL shortener showed 'Link Not Found' on Safari but worked fine on Chrome. The root cause: a browser-level JS execution difference.

Three days to get a 'simple' OAuth integration working with Zapier. Here's what I learned about filter chains, race conditions, and PKCE.