How I Migrated an Untested Codebase with Loops and an AI Harness

I was handed a SaaS running on Firebase that had to move to Supabase, on a very low budget. This article covers the techniques I used to get it done with an AI harness. Starting point The application was a Nuxt.js SaaS with 20 large screens running on Firebase, already written in TypeScript. It worked as a workflow that enriched business data step by step. Users could manage multiple projects. Each project was owned by one or several “managers”, who could invite “contributors” to go through the workflow. That implied a role system. There was also an admin area. ...

August 8, 2026 · 6 min · Flavien Jourdren