AI Senior Software Engineer

About this job

Deine Mission About Wallround Wallround is headquartered in Berlin, with additional locations in Hamburg, Frankfurt am Main, Munich, Friedrichshafen and NRW. Our mission: we turn energy-efficient retrofits for multi-family residential buildings into predictable, lucrative investment opportunities. When it comes to modernisations, the real estate market is often a black box of rough estimates and fragmented processes. We are changing that. Through our integrated platform and streamlined workflow, we transform 'brown assets' into future-proof, high-yield properties. About the Role Department: Prod & Tech Functional Home: AI Reports to: CPO Location: Berlin, office-first Seniority: Senior We are looking for AI Senior Software Engineers to design and build the technical foundation behind our AI-powered products. You will be part of the AI Functional Home while working primarily within cross-functional product squads. You will collaborate closely with the AI Lead Product Manager, Product Design, Full-Stack and Backend Engineers, and Automation Engineers. This role is ideal for an engineer who enjoys moving between AI experimentation and production software engineering - taking an idea from prototype to reliable, scalable customer-facing functionality. Key Responsibilities AI Engineering • Design and implement production-grade AI features and services. • Work with LLMs, multimodal models, embeddings, RAG, agents, and AI APIs. • Design AI workflows that are reliable, observable, and maintainable. • Evaluate models and AI approaches against product requirements. • Develop strategies for accuracy, hallucination reduction, latency, and cost optimization. Product Development • Work directly with the AI Product Manager to turn product requirements into technical solutions. • Rapidly prototype new AI capabilities and validate technical feasibility. • Take successful prototypes into production. • Contribute to technical product decisions and architecture. AI Infrastructure & Quality • Build evaluation frameworks and testing approaches for AI systems. • Implement monitoring and observability for AI applications. • Establish appropriate guardrails and fallback mechanisms. • Monitor model performance, latency, availability, and cost. • Help establish reusable AI infrastructure and engineering patterns. Cross-Functional Squad Execution • Act as a senior technical contributor within the AI Product Squad. • Collaborate with Product, Design, Backend, Full-Stack, and Automation specialists. • Break complex AI initiatives into executable technical work. • Mentor other engineers and raise engineering standards across the AI Team. • Participate in architectural and technical decision-making. Dein Profil What We are Looking For • 6+ years of professional software engineering experience. • Significant experience building production software using TypeScript and/or Java Python. • Hands-on experience building applications with LLMs or other modern AI technologies. • Strong understanding of APIs, distributed systems, databases, and cloud infrastructure(AWS, GCP, or Azure). • Experience taking AI prototypes into production. • Strong software engineering fundamentals: testing, version control, code review, observability, and maintainability. • Ability to operate autonomously in a fast-moving product environment. • Experience with RAG architectures and vector databases. • Experience building AI agents and tool-calling systems. • Experience with model evaluation and AI observability. • Experience with LangChain, LlamaIndex, or equivalent frameworks. • Experience with multimodal AI. • Experience building B2B SaaS products. Success in the First 6–12 Months • Deliver production-grade AI capabilities. • Establish reliable AI engineering and evaluation patterns. • Improve the quality, reliability, and cost efficiency of AI features. • Build reusable AI components that accelerate future squads. • Mentor engineers and contribute to the technical direction of the AI Team. What You’ll Own AI Architecture → AI Engineering → Production AI Systems → Evaluation → Reliability → Technical Excellence Warum wir? Why Join Wallround? • Impact: Shape the future of energy-efficient retrofits and make a real contribution to climate action. • Growth: Be part of a fast-growing startup with huge market potential. • Team & Culture: Work alongside a highly motivated, experienced team in Berlin (Kreuzberg). Enjoy a vibrant startup culture, regular team events, and a modern workplace. • Innovation: Flat hierarchies and fast decision-making—your ideas matter from day one. • Flexibility & Development: Competitive salary, flexible working hours, and tailored personal growth opportunities. • Perks & Benefits: €150 monthly benefit budget—use it for public transit tickets, meal allowances, or lifestyle perks (e.g., Urban Sports Club membership or vendor vouchers).