Senior Full-Stack Engineer (AI-First) (w/m/d)

TwinCloud builds AI-powered software that helps Germany's largest real estate and housing companies decarbonize their buildings. Using computer vision and 3D Gaussian Splatting, we turn ordinary camera footage into measurable digital twins with actionable insights, making heating replacement and energy efficiency measures scalable across entire portfolios. Founded in January 2026 and backed by Fraunhofer's Deep Tech Venture Lab, we closed our first funding round in March and already have paying customers and pilot projects with several of Germany's largest housing companies. We're a team of seven on a strong growth path. We're looking for a senior full-stack engineer who works AI-first without sacrificing engineering quality. You'll work directly with the founders and shape core technical decisions from day one. Build and ship features across our full stack: web frontend, backend, and occasionally our Flutter mobile app Drive our web stack forward: currently some vanilla JS/TS, with a likely move to React that you'd help evaluate and lead Design, deploy, and operate our cloud infrastructure (Azure, Scaleway, GPU compute) Run and scale the GPU-based computation pipelines that turn video into 3D models Own our backend and application architecture (Supabase/Postgres) Improve deployment, monitoring, and operational reliability Provide technical guidance to less experienced developers and working students Iterate rapidly on customer feedback and challenge our workflows: Not "this is bad," but "why don't we do it like this?" 5+ years building production software full-stack (strong candidates with 3–4 years will also be considered) A hands-on coding background, and now highly productive with AI tools like Claude Code. You read tickets, understand code before changing it, and know when to close the AI session and think Solid web development skills (JS/TS); experience with or strong interest in React Experience operating cloud infrastructure and compute-intensive workloads Strong Postgres/backend experience; hands-on Supabase experience is a big plus High ownership and an independent work style; you keep the architecture overview, not just your own tickets Fluent English Master's degree in a relevant technical field, or equivalent practical experience Nice to have: Flutter, GPU workloads, CI/CD ownership, ML product experience, German Our stack: Flutter/Dart, JS/TS, Supabase (Postgres), Azure & Scaleway, GPU compute, GitLab, VS Code, Claude Code. Competitive salary plus virtual shares (VSOP), real upside in a fast-growing deep-tech company Work directly with the founders and own meaningful technical decisions Build products used by Germany's largest housing companies, with real climate impact A modern, AI-first codebase with no legacy burden High autonomy and real responsibility during rapid growth Hybrid work from our Berlin office (near U Ernst-Reuter-Platz) Send us a short note about yourself and something you've built, a repo, a product, a war story. No cover letter needed. Start date: as soon as possible.