Software Engineer - AI

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.