Senior Software Engineer (.NET / Angular)

AI-Assisted Development of a Document Management System

Remote · Full-time

The project
We are building a new document management system for the German market — from the ground up, with a clear ambition: GoBD-compliant, audit-proof archiving, e-invoice processing (XRechnung, ZUGFeRD) as a core capability, and certifiability under the IDW PS 880 audit standard as the goal. Technically, we are creating a multi-tenant SaaS platform designed as a modular monolith: ASP.NET Core (.NET 8), Angular, PostgreSQL (database-per-tenant), S3-compatible object storage with WORM immutability, Keycloak, and qualified timestamps.
What makes this special: there is no legacy system and no grown codebase — instead, a well-developed architecture concept, a fully sliced backlog, and a development process that has been formalized from day one (mandatory reviews, test obligations, full traceability), because for a certifiable product, the development process itself is part of the audit.

Your role
You will develop and test the application primarily AI-assisted — with agentic coding tools (e.g. Claude Code or comparable) as an integral part of your workflow. This does not mean less responsibility; it means a different kind: you translate functional requirements and architectural constraints into precise instructions for AI tools, you review and own every line of the output, you harden it with tests, and you take it through our review process. The AI accelerates — the quality, security, and architecture decisions are yours.

In practice, you will:

• Implement user stories from our backlog as vertical slices — from data model through API to the Angular frontend — using AI tools deliberately for implementation, test generation, and refactoring
• Review AI-generated code with expert judgment: architectural conformity (module boundaries, tenant context, policy enforcement), security, and compliance invariants (immutability, audit completeness) are non-negotiable
• Implement and extend our test strategy: unit, integration (Testcontainers), and E2E tests, including the special cases of an archiving system (WORM behavior, audit hash chains, tenant isolation)
• Contribute to architecture decisions (ADRs) and help maintain procedural documentation — both of which are subject to the PS 880 audit we are preparing for
• Help shape our AI-assisted way of working itself: prompts, project context, guardrails, and automations that make the tools better

What you bring

• Several years (5+) of professional software development experience with C#/.NET (ideally ASP.NET Core Web APIs) and solid knowledge of Angular or a comparable SPA framework
• Experience with relational databases (PostgreSQL preferred), EF Core, and container environments (Docker)
• Hands-on experience with AI-assisted development — you have used agentic coding tools productively and have a realistic sense of what they can do, where they fail, and how to verify their output
• A strong quality and testing mindset; you see reviews, mandatory tests, and documented changes not as friction but as craftsmanship
• Interest in regulatory requirements (GoBD, audit-proof archiving) — prior knowledge is a plus; diligence and willingness to learn are a must
• Nice to have: OpenID Connect/Keycloak, S3-compatible object storage, background job systems (Hangfire), e-invoicing standards, Transloco
• German language skills at B2 level are desirable, not required (procedural documentation and domain terminology are German); the working language within the team can be English

What we offer

• A greenfield project with a well-thought-out concept instead of legacy maintenance — and the chance to shape an AI-first engineering culture from the start
• Short decision paths and direct collaboration with the product owners
• Fully remote work format, flexible schedule

Interested?

Please send us your application — ideally with a brief example of how you have used AI tools in a real project (what worked, what didn't?). That conversation interests us more than any buzzword on a CV.