.NET · JavaScript · Dynamics 365 · AI
Senior engineers who join your team and deliver from sprint one.
We extend in-house engineering teams in DACH and the UK with senior .NET, JavaScript and Dynamics 365 developers, analysts and testers. They work in your sprints, we handle the rest.

Your first call is with Rado, co-founder.
Boutique team. Senior people. Straight answers.
Trusted by engineering teams at








What we do
How we help engineering teams
Team Extension
Add senior .NET or JavaScript engineers to your team in two weeks. They join your stand-ups, your repo and your tools, managed and backed up by us.
Team Extension →.NET & JavaScript Development
Web platforms, APIs and modernisation of existing systems in .NET, Angular and Node.js, built and maintained by a team that stays with the product.
.NET Development →Dynamics 365 & Power Platform
Customisation, integrations and clean-up of Dynamics 365 CRM, from plugins and solution structure to .NET extensions.
Dynamics 365 →AI Development
AI built into the systems you already run: assistants on your own documents, document processing and workflow automation, integrated with your data and security rules.
AI Development →What our engineers work in every day
How we work
From first call to first commit in two weeks
Call (30 min)
You tell us what your team needs. We tell you honestly whether we are a fit.
Profiles in 2 days
Hand-picked senior engineers, not a stack of CVs.
Interview
You meet and approve every person who joins your team.
Start
Your new teammates join your next sprint. We stay accountable for quality and continuity.
Why Appstronauts
Boutique team, enterprise‑grade delivery
We stayed small on purpose. You get senior people, one accountable partner and a founder who knows your project.

- 01
Senior by default
People who make decisions, not people who need them made. You interview everyone before they start.
- 02
A full team, not just coders
Business and system analysts, PMs and testers are in-house, so we can cover the gaps around your developers too.
- 03
You talk to the founder
We are small enough that Rado knows every project and big enough to scale your team when you need it.
- 04
Close to you
Central European time, English and German, a short flight from Berlin, Zurich, Vienna and London.
In person
Real people, not a vendor portal
We meet our clients regularly, in person. We work as part of their team, not as an outside vendor, and we show up at the industry events where our clients are, from huge industry conferences to niche local tech meetups.





Security & trust
Ready for your procurement and security review
We work with companies like Cisco and EF Education First, so the paperwork is part of the job. Whatever your policies require, we sign and follow.
NDA, before anything else
We sign your NDA before you share anything about your project.
Data Processing Agreement
A GDPR-compliant DPA whenever we process personal data on your behalf.
Professional liability insurance
Our work is covered by professional liability (OC) insurance, with details for your procurement team on request.
Your hardware, your accounts
If your security policy requires it, our engineers work only on your laptops, VPN and accounts.
Certified engineers
Most of our engineers hold Microsoft, AWS, Google Cloud or Claude certifications.
AI on your terms
We agree up front which AI tools and models can be used on your code and data, and nothing else is.
What clients say
Rated 5.0 on Clutch from 28 verified reviews
“Appstronauts treated us like a partner and did their best to provide a product that complied with our requirements.”
Verified review on Clutch · 5.0
“Appstronauts’ strength is the availability of their team.”
Verified review on Clutch · dedicated team since 2016
“Appstronauts treated us like a partner rather than a client. They were personable and invested in our success.”
Verified review on Clutch · 5.0
Recognised by





Let’s talk
Need senior engineers on your team?
Hi, I’m Rado, co-founder of Appstronauts. Book 30 minutes with me. No sales deck: tell me what your team needs and I’ll tell you honestly whether we can help.
or email radek@appstronauts.co



