From Side Project to SaaS

The moment your side project generates its first euro — everything changes.

Energy Backbone started as a tool I built for a friend who runs a marina. He needed to track electricity usage per boat berth and charge tenants accurately.

Simple problem. I built a solution in two weeks.

Then he asked: „Can other marina operators use this?“

That question turned a side project into a SaaS product.

The milestones that actually mattered:

🔑 First paying stranger — Someone I’d never met found the product, tested it, and entered their credit card. That was the moment it became real.

📊 First automated invoice — When we sent an invoice without me touching anything, I felt like I’d unlocked a cheat code for business.

🔁 First churn… and first win-back — A customer left. I asked why. Fixed the issue. They came back. That feedback loop taught me more than any book.

📞 First support call — A marina operator in Northern Germany called me because a meter reading looked wrong. I fixed it in 20 minutes. He’s still a customer.

What nobody tells you about going from side project to SaaS:

The code is 30% of the work. The other 70% is billing, support, onboarding, documentation, compliance, and answering emails.

Full story in my article series 👇

This is part of my 7-part series on vibe-coding. Follow along to see what happens when a non-developer starts building.

This post is part of my series on vibe-coding and building apps without traditional coding skills. All articles in the series →