Product Engineer (Backend/AI)

Global enterprises face overwhelming operational complexity collecting, verifying, and acting on sustainability data. We are building the core backend infrastructure and agentic workflows to automate this critical layer of the climate economy. In this role, you will bridge solid backend engineering and cutting-edge LLM systems to deliver real-world production reliability.

Full end-to-end lifecycle of core backend infrastructure and applied AI capabilities across our platform.

• Architect and ship scalable backend systems, APIs, and data models using Python, FastAPI, and PostgreSQL.
• Build and optimize production applied AI features, including RAG pipelines, LLM chains, structured outputs, and tool-using agents.
• Establish evaluation workflows and performance benchmarks to monitor and improve AI latency, cost, and reliability.
• Strengthen platform observability, CI/CD pipelines, containerized deployments, and automated testing suites.
• Collaborate directly with users and product peers through technical design reviews, pragmatic iteration, and pair programming.

• Proven track record shipping reliable production backend systems in Python.
• Direct experience building applied LLM features like RAG, agents, and evaluation pipelines.
• Prior experience thriving in lean engineering teams (5–20 engineers) with high ownership.
• Strong foundation in testing, CI/CD, observability, and containerized cloud environments.
• Pragmatic builder who communicates clearly in English (C1+) and enjoys technical collaboration.
• Authorized to work in Germany or the United Kingdom.

Our company fosters a high-ownership, mission-driven, and low-ego environment focused on using AI for climate and sustainability impact. The team operates with trust, high autonomy, and direct collaboration (including pair programming and technical design reviews) within a fast-paced startup dynamic based in Berlin and London. Team members value pragmatic iteration, thoughtful debate, and continuous learning via quarterly hackathons and learning budgets.

• High autonomy and end-to-end product ownership on a lean, mission-driven team.
• Collaborative, low-ego environment featuring pair programming, design reviews, and quarterly hackathons.
• Dedicated continuous learning budget to support your technical growth.
• Work hub access at vibrant AI innovation ecosystems in Berlin or London.

Python · Backend systems design · API design · Database design · Applied AI / LLM engineering · RAG · Cloud & Containers · CI/CD & Testing · FastAPI · PostgreSQL · LangChain · LangSmith · B2B SaaS · AI latency/cost optimisation · ESG domain knowledge

This probably isn't for you if:

• You prefer siloed task assignments over end-to-end product problem solving.
• You treat LLMs as black-box toys rather than production systems requiring rigorous evaluation and latency/cost optimization.
• You dislike collaborative practices like pair programming, code reviews, and direct user feedback.

If you want to build high-impact, production-grade AI systems for the global sustainability economy, we would love to review your application and 2-minute intro video. Apply today to start the conversation.