AI Senior Software Engineer

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

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.

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

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).