Senior Full-Stack Developer / AI Engineer / Data Scientist (m/w/d) (German speaking)

sandan AI is a Berlin-based AI-native startup building a platform for agentic marketing workflows. We are looking for a Senior Full-Stack Developer / AI Engineer / Data Scientist to develop full-stack applications, ML models, and LLM-based agents. The role involves working with modern JavaScript/TypeScript, Python, and AI tools like Claude Code and Codex.

• Develop and maintain full-stack applications using React, Next.js, Node.js, and Nest.js
• Design and optimize relational databases (PostgreSQL, MySQL, MS SQL)
• Containerize and orchestrate services with Docker and Kubernetes
• Build data pipelines, feature stores, and ML workflows for agentic systems
• Train, evaluate, and deploy machine learning models for marketing use cases (attribution, targeting, forecasting, anomaly detection)
• Implement RAG pipelines with embeddings, vector stores, and re-ranking
• Set up LLM evaluation frameworks, prompt optimization, and quality benchmarks
• Use code harnesses (Claude Code, Codex) in daily development

• Several years of full-stack development experience
• Proficient in TypeScript, JavaScript, React, Next.js, Node.js, Nest.js
• Experience with relational databases and container technologies
• Solid Python skills with ML stacks (pandas, NumPy, scikit-learn, PyTorch or TensorFlow)