We’re looking for a Senior Backend Developer who challenges assumptions, builds with intention, and thrives in a fast-moving, AI-driven environment.
At 3ap, engineers own their work end-to-end. Our teams run on separate projects but solve hard problems together, share what they learn, and call out bad assumptions, including their own.
What we need:
- 5+ years of experience building backend systems with Java (Spring) and its ecosystem
- Track record of shipping production-ready applications, including ones that integrate LLMs and unstructured data
- Strong REST API design and integration experience, and solid understanding of microservices architecture
- Hands-on with Docker, Kubernetes, Jenkins, and OpenShift
- Rigorous about testing and validation, especially where AI outputs are non-deterministic
- You think about the full product, not just your layer. A bad integration can sink a good solution
- You’re an exceptional communicator, comfortable talking to designers, frontend engineers, product managers, and stakeholders, and presenting your work to non-technical people
- You’ve gone deep into AI tools, not just used them casually, and know how to get real production value out of them, while treating AI output as a draft, not a deliverable
- You’ve used GitHub Copilot, Claude, or similar in your actual workflow, and you build guardrails around what they produce
- You don’t stop at “it works.” You look for the flaw in the logic before someone else finds it in production
- You pick up new tools fast. The AI landscape shifts week to week, and waiting to learn something familiar isn’t an option
- University degree in CS or equivalent
- Fluent English
Useful, but not required:
- Node.js, TypeScript, PostgreSQL, or MongoDB
- Frontend experience with React, Angular, or Vue
- CI/CD and DevOps hands-on experience
- Familiarity with API tools like Postman or Insomnia
- Prompt engineering or multi-step AI workflows
- Comfort and openness to working with Python. Many modern AI tools and frameworks are built with Python at their core, so a willingness to learn and use it is important
- Background in insurance or finance
- Any German
What you get:
- A team of 60+ professionals in a people-first culture, flat structure, and no bureaucracy
- Work that uses current technology, including AI in production
- Flexible hours, hybrid work
- 25 vacation days + 2 extra 3ap holidays
- Private pension, private health insurance, 24/7 accident insurance
- Maternity and paternity leave support
- Team events and an employee referral program
