Software Engineer - AI

Role details

ABOUT THE ROLE Join a 15-person B2B construction technology startup as a Software Engineer – AI, owning end-to-end AI features that solve real problems for construction professionals. You'll sit within the Product & Engineering team, working across the full stack — from database schema and LLM optimization to UI — while building platform foundations that allow new use cases to ship in roughly a month. WHAT YOU'LL DO - Build and own end-to-end AI features from concept through production, including document versioning and agentic chat workflows. - Design and implement features across the full development lifecycle: database schema, LLM tuning, evaluation, and UI. - Manage evaluations, scoring, and error analysis on new and shipped AI features to ensure consistent quality. - Contribute to the workflow harness, decision-trace standard, and evaluation tooling that accelerates shipping new use cases. - Build reusable human review and approval surfaces that establish trust in AI output. - Model and evolve a construction ontology and project graph, including entity resolution across documents such as bills of quantities, contracts, and drawings. - Design features that link answers to evidence and make decisions auditable and traceable. - Extend multi-modal ingestion of unstructured documents — PDFs, scans, drawings, and 3D models — at scale. - Build read/write integrations with customer systems (document management, ERP) to complete workflows end-to-end. - Contribute to scalable data pipelines and support native BIM/DWG file processing. WHAT WE'RE LOOKING FOR - 3+ years of full-stack software engineering experience in fast-paced, B2B startup environments. - Proven track record delivering production-grade applied AI features to customers. - Proficiency in TypeScript, Python, and SQL for building full-stack applications. - Experience building backend APIs and database schemas (e.g. Fastify, Prisma, or equivalent). - Experience integrating and optimizing LLM APIs (e.g. OpenAI, Azure, Gemini, Cohere, or similar). - Experience with cloud infrastructure such as AWS (RDS, S3, Elastic Beanstalk) or equivalent. - Experience building data pipelines and ETL workflows for processing unstructured data at scale. - Experience with vector databases and semantic search implementations. - Experience designing and implementing evaluation frameworks and error analysis for AI systems. - Experience building internal platform or developer-facing tooling that other engineers ship on top of. - Startup exposure or early-stage founding experience; comfort with autonomy, ambiguity, and end-to-end ownership. - Fluent spoken and written English; German is a genuine plus but not required. - Familiarity with workflow orchestration tools (e.g. Prefect, Airflow), document processing/OCR, or observability tooling (e.g. Datadog, Langfuse) is a bonus. COMPENSATION & BENEFITS Salary range: €80,000 – €120,000 per year. Visa sponsorship is not available for this role. LOCATION On-site, five days per week in Berlin, Germany. Candidates must be based in Berlin or willing to relocate.