Engineering notes — things I keep re-explaining, written down once.
- Best OpenAI-Compatible One-Key API for a Node.js US/EU SaaS Chatbot
- GDPR Object Storage Design for Private App File Upload and Signed Download
- Node.js App Logging API: Structured JSON Logs, Request IDs, and Backend Ingest
- Multi-Model API Selection for Small Teams: OpenAI, Claude, Gemini, and Lock-In
- Welcome Email Deliverability Checklist for SaaS Custom Domains and DKIM
- Private file storage for user-uploaded documents: signed URLs and S3-compatible options