This one started years ago when a family member needed a booking system for their motorbike driving school. I built something that worked, and it's been running since.
It's not exactly a fun project, but I have to rebuild it. Emails stopped working properly, and Firebase keeps sending me notices about deprecated features. That said, the Firebase stack was surprisingly nice — it cost me about 5 cents a month and the tools were straightforward. I was just never a big fan of the document data store. The app has a few many-to-many relationships and Firestore didn't support transactions at the time (or maybe it did and I missed it), so I had to twist my head to make it work. Good enough for a start, though.
The rebuild is multi-tenant this time, so it can serve more than one school. Next.js on Vercel, Neon for the database, Resend for emails. That combo has been great for moving fast.
Fun note — the whole rebuild was pretty much done in three days from my couch using Claude. Amazing, but I'm losing control over the codebase and it freaks me out a bit. I try to focus on the data model to keep things sane, and I keep features to a minimum so there's less code to worry about. I do review what comes out, but honestly, not all of it. And the "I'll do a proper security review later" plan is causing some anxiety — we all know later never happens. I need to find a better way to work with these tools.
Still a work in progress. More on this as it takes shape.