Senior Backend Engineer - AI Agents - Climate Tech (all genders) gesucht in Berlin

As a Senior Backend Engineer - AI Agents (m/f/d), you will shape how AI is used in our Corporate Carbon Footprint (CCF) and Product Carbon Footprint (PCF) workflows.

Your focus is on building reliable, production-grade LLM-based systems and integrating them cleanly into our backend architecture. This is not a research role. It's about making AI systems understandable, reproducible and trustworthy in a data-heavy, audit-relevant product.

You will work closely with the CTO, product management, senior engineers and sustainability experts, combining hands-on implementation with architectural responsibility.

You will work on:

• Designing and implementing agent-based LLM systems (tool calling, orchestration)
• Applying RAG to ground AI outputs in internal data
• Defining evaluation, quality control patterns and uncertainty signals for AI-generated results (e.g. LLM-as-a-judge)
• Combining AI-driven logic with rule-based mechanisms for reproducibility
• Making informed trade-offs between accuracy, cost, latency and reliability in production

You will not be building or training foundation models.

Tasks

• Own the backend services (agents) for AI-driven PCF and CCF workflows
• Implement and evolve agent orchestration, evaluation and quality mechanisms (ML Ops)
• Set technical direction for AI-related backend systems together with the CTO and other senior engineers
• Translate product and domain requirements into robust technical solutions
• Ensure code quality and knowledge sharing through code reviews and collaboration

Selective Technologies we use

• Languages: Golang, Python (FastAPI)
• Agents: Langgraph, Langfuse
• LLMs: self-hosted inference backends with battle-proven state-of-the-art models
• Messaging & Data: NATS, Postgres, Redis

Are you tired of working on products you don't really care about?

Do you want to work on something that has a positive impact on humanity and our planet? Do you like to get stuck in and are you passionate about coding? Then we have a great opportunity for you., Must Haves

• 5+ years of experience in backend software development
• Strong Python skills
• Proven track in agent development in a professional environment
• Strong familiarity with agent frameworks, technologies and techniques (RAG, tool-calling, function-calling, agent design patterns)
• Experience balancing performance, cost and accuracy in production environments
• Fluent in English, clear written and verbal communication (German is a plus)
• You live in the EU (CET ±1) with a valid work permit
• You are passionate about the fight against the climate crisis and creating customer-oriented solutions that deliver real added value
• Startup or scale-up experience

Nice to have

• Experience in data-heavy or audit-relevant domains
• Degree in computer science or a related field

• Creating long-lasting software with a positive impact - we are here to stay
• Play a decisive role in shaping our product and corporate culture
• A mission that drives us every day
• Fair compensation (first order of magnitude: around € 70,000 - 80,000 gross depending on experience)
• 28 vacation days and flexible vacation planning (you don't have to plan your entire vacation at the beginning of the year)
• Flexible working hours - family-friendly :)
• 100% remote is possible - work from your preferred location
• Freedom to contribute to the open source community
• Teamevents

At Global Changer, you will work on a solution with a clear goal: helping companies reduce emissions faster. We focus on one of the biggest levers to fight the climate crisis and work mainly with large organisations. We are backed by well-known investors (including neosfer, part of the Commerzbank Group, and the former CIO of innogy) and work with renowned customers such as Heraeus, Tchibo and Haniel. Our goal is to reach as many companies as possible worldwide with our software and contribute meaningfully to reducing emissions. Impact is therefore one of our core values. About the software Our product is a SaaS B2B platform that supports companies along their sustainability journey, with a strong focus on carbon accounting (Corporate Carbon Footprint (CCF) and Product Carbon Footprint (PCF)). We use AI to support data-heavy workflows and to generate estimates where data is incomplete, always with the goal of improving data quality over time.