Product & growth studio — Mitte, Berlin & Churwalden, Switzerland
Four senior builders. We lock in what you get, what it costs, and when you launch before writing a line of code — MVPs in 8–12 weeks, AI agent pilots in 3–4, growth engineering by the month.
Engagement drawings
| # | Item |
|---|---|
| 1 | Product design & UX |
| 2 | Web or mobile app |
| 3 | Auth, payments, admin |
| 4 | Deploy, docs, handover |
SELECTED WORK
Web apps, mobile products, and autonomous AI agents designed, engineered, and launched for founders and operators.
BERLIN · AI & AGENTS
Omnichannel guest messaging where the model classifies and proposes, and a deterministic policy gate — not the model — authorizes anything that touches money or a door lock.
MOBILE & AI · EDUCATION
Cross-platform mobile app and scalable backend utilizing AI-generated mnemonics and gamified spaced repetition to drive long-term vocabulary retention.
SPORTS ARENA · FULL-STACK & PAYMENTS
Full-stack arena management system: Django REST Framework API over PostgreSQL, React customer portal, real-time slot inventory state machine, and automated mobile payments.
SARGANS, SWITZERLAND · LUXURY SALON
High-end digital experience with interactive treatment discovery across 13+ specialized services, international trilingual routing (DE/EN/FR), and integrated booking.
engagement models
Idea to launched product in 8–12 weeks. Design, build, deploy, handover — scoped and priced before we start.
From $10K. Web or mobile, with AI features where they earn their keep.
One working AI agent in your real workflow in 3–4 weeks — support triage, document processing, lead qualification.
From $7.5K. You keep the code, prompts, and evals — whether or not you continue.
Ongoing product and growth work: features shipped weekly, technical SEO, performance, and analytics.
From $2.5K/month. Scale up or down monthly — no lock-in.
how we work
Fasten Teams is a remote-first product studio of four senior builders. We design, build, and launch web and mobile products — and the AI features and growth engineering around them. No account managers, no hand-offs: you work directly with the engineers writing your code.
client words
Let's talk
