(Senior) Full-Stack Software Engineer (m/w/d)
Posted 2 days 19 hours ago by 20 GmbH
Salary: 60.000 - 65.000 € per year
Requirements:- High quality standards: while moving fast, you still care deeply about code quality and architectural soundness of the product.
- Fluency with AI-assisted / agentic development: hands-on experience driving tools like Claude Code to build real, non-trivial features, plus the discipline to review and verify their output rigorously.
- Strong 3D graphics engineering with Three.js / WebGL: scene, camera & projection math, raycasting/picking, mesh/BufferGeometry processing, render-loop performance.
- Fluency in React + TypeScript
- Backend competence in Node/TypeScript + relational SQL: NestJS or similar, PostgreSQL, transactions, concurrency.
- Mathematical & geometric literacy: enough to understand theoretical concepts, read algorithmic code and research papers.
- Product-minded and comfortable owning an under-documented, reverse-engineered problem space.
- Extend the 3D/CAD editor: new element types (windows/openings, rooms, zones, HVAC), multi-storey support, richer editing tools.
- Build out real-time multi-user collaboration
- Improve and verify the geometry engine and the IFC / CAD exporters: reconstruction quality, normalization, export fidelity.
- Own features across the full slice: Postgres schema NestJS domain REST/WS API React/Three.js UI.
- 3D
- AI
- API
- BIM
- Backend
- Claude Code
- Computer Vision
- GIS
- Support
- NestJS
- PostgreSQL
- REST
- React
- SQL
- TypeScript
- WebGL
- Windows
- UX UI Design
- NodeJS
- JavaScript
- ThreeJS
- opencv
- Fullstack
More:
Buildings account for 35% of green house gas emissions in the EU. To accelerate the transition down to zero, we build browser-based SaaS for the German building-energy-renovation market. Our product pulls a real building from cadastral LOD2 data, floor plans and facade photos, reconstructs it as a clean, editable 3D model in the browser, and exports it to industry formats for downstream energy calculations and grant applications.
It's a technically deep product: a versioned, real-time-capable, multi-user 3D building editor backed by a purpose-built geometry and computer vision engine. Much of the hardest code was and will be produced with agentic AI tooling under close human direction and review. We're looking for someone who works the same way.
- Small and ambitious team, high ownership, a genuinely hard problem and a rare chance to do serious work at the pace AI-assisted development makes possible.
- We're already an AI-first team: the tooling, conventions, and dense in-code documentation are built around that workflow, so you'll be productive in a deep domain far faster than the domain would normally allow.
We offer a competitive compensation package including a base salary, bonuses for reaching product milestones, equity (VSOPs), tax benefits and public transport.
last updated 29 week of 2026