Stefan Ostermann Software consultant and founder of Alstapp GmbH
Software at a fixed price and AI that stays in-house.
For mid-sized companies that need predictable costs and will not hand their data to someone else.
Twenty years of experience with software that scales help with that. Most recently as Head of Development, now independent in Hamburg.
About
After many years leading software and product development, most recently as Head of Development, I have been independent since October 2026. What used to need a team can now be done alone, because agents handle the grunt work in the background. Alongside that, I am founding Alstapp GmbH for local AI in small and mid-sized businesses.
I use established technology and new methods: custom software at a fixed price, built on proven design patterns and with AI assistance. I comply with the GDPR and work to ISO 27001. Whether a project uses private or public AI depends on what it processes.
The time that used to go into meetings and coding by hand now goes into specification and into working with people.
Alstapp GmbH
I bring local AI for small and mid-sized offices together in Alstapp GmbH, a company from Hamburg-Barmbek that is currently being founded. It runs language models on hardware at the client's premises and automates recurring office work, without data leaving the building.
The path is fixed: a half-day workshop on real files, a pilot at a fixed price, then rollout and operation. Custom software at a fixed price is still offered here.
Availability
I am available now for projects, sparring and partnerships.
I am starting solo, with a clear plan to grow together with a partner.
What I offer
Custom Software
I build software end-to-end, from analysis through development to operation. AI-assisted, so it moves fast. Your code and data stay 100% in-house. You pay a fixed price instead of a daily rate. Behind that are sixteen years of work on platforms handling up to 100,000 orders a day.
Private & Local AI
Open models like Gemma or Qwen on your own hardware. Contracts, customer data and source code stay inside the company. From choosing the hardware to day-to-day operation.
Information Security & Compliance
I have worked hands-on through ISO 27001 and TISAX certifications and built GDPR-compliant systems. I have run pen tests and I train developers on the OWASP Top 10. When a certification is coming, I take you through it. For German Mittelstand companies that have to take security and data protection seriously.
Experience
- since October 2026
Independent Software Consultant
Stefan Ostermann, Hamburg
- 2025 — 2026
Head of Development
eos.uptrade (Siemens Mobility), Hamburg
- 2018 — 2025
Director Product Development novomind iSHOP
novomind AG, Hamburg
- 2015 — 2017
Project & Partner Management novomind iSHOP
novomind AG, Hamburg
- 2009 — 2015
Project Lead novomind iSHOP
novomind AG, Hamburg
- 2005 — 2009
Software Developer
Various Companies
- 2005
Diplom-Informatiker (FH), Computer Engineering
Osnabrück University of Applied Sciences