I build backends that hold up when real money is on the line.
Fifteen years across fintech and health tech. I took a Ghanaian money app from zero to 580,000 users and GHS 2.6 billion moved, and helped scale a mental health platform to 25 million covered lives. Now I work with a small number of companies as a fractional CTO, alongside focused consulting.
Three ways to work with me
Fractional CTO
For companies that need senior technical leadership but not a full-time hire. I own your architecture, your team, and your technical decisions, a few days a week.
How it works →Consulting
For teams with an existing system and a specific problem: architecture reviews, scaling and reliability, delivery, AI adoption. Spot engagements and working sessions.
What I take on →Building business applications
For teams that want the system built and shipped, not just advised on. CRMs, internal tools, dashboards, and WhatsApp or USSD products, delivered end to end through Fayaworks on a platform that ships in weeks.
Radioactive Labs →Selected work
Achieve, an investment app for the Ghanaian market
Built the team and architecture from zero. Grew to 580,000+ users, 226,000 of them paying, with over GHS 2.6 billion moved (USD 150M+). Rails backend, Flutter app, and the internal operations tooling behind it all. Nominated for Fintech CTO of the Year 2025.
On-demand mental health, at 25-million-life scale
Member-facing backend as the platform grew from 500k to 25M+ covered lives across 50+ countries. Owned live coaching features where a member reaches a human in under 60 seconds, at any hour, under HIPAA.
Engineering leadership across partner teams
Led engineers delivering software for Andela partners including Ginger and Crux Informatics. Mentored and assessed developers in training, ran engineering and management workshops, and conducted hiring interviews.
Custom CRM and back-office automation
First developer on the team. Built a CRM with integrated help desk and automated statements, including rebuilding a statement run that took over a week to finish in about two hours.
Tools I write and maintain
Open-source Rails tools I built for my own work and still maintain. They also power the products Fayaworks ships.
Want a product built on them end to end? That is Fayaworks →
About
I'm Stefan Froelich, a software engineer in Accra, Ghana. I've been building for 15 years: .NET, Django, Android and Flutter before settling mainly into Ruby on Rails in 2019. I've built engineering teams from zero and I still ship code myself, with coding agents in the loop daily, not as a demo.
Most of my career has been in places where mistakes cost money or trust: consumer fintech and clinical mental health. That shapes how I build. Boring architecture, real monitoring, and software a business can actually run on.