Engineering notes — things I keep re-explaining, written down once.
- Troubleshooting 400 Bad Requests for Structured Health Check Logs
- Simplest Failure Alert Stack for Small SaaS Errors, Logs, Metrics, and Slack
- SMS OTP vs Email OTP for US and EU SaaS Login: Security, Delivery, and Fallbacks
- Next.js and Node.js Cron Job Heartbeat Monitoring for Missed Runs
- Choosing Error Tracking for Express APIs: Stack Traces, Grouping, Search, and GDPR
- Multipart upload of a large AI-generated image to S3-compatible object storage in Node.js
- Private file upload architecture: signed upload and download for GDPR object storage