IoT Platform Engineer - Energy Systems (f/m/d)

Tasks
FION Energy develops software for the dimensioning, intelligent control, and monitoring of industrial energy storage and PV systems. Our AI-driven platform optimizes battery operations across peak shaving, self-consumption optimization, spot market trading, and flexibility marketing, cutting electricity costs with payback periods of 2-4 years. We're a Berlin-based team with paying customers and batteries already running in the field.
Our mission is to build a truly end-to-end platform - from ML and optimization, through data streaming and control, to the edge device sitting at the customer site. We're looking for an engineer with deep experience in edge and IoT systems to join us as an early hire. You'll work on our cloud data and control platform, our own edge stack, and different edge and cloud integrations - whatever matters most for the business right now. This is a startup role: you should be comfortable switching between strategic thinking and hands-on work.
You'll work directly with the CTO and co-founder.
Requirements
You bring:
* 5+ years of professional software engineering experience
* Hands-on experience deploying and managing IoT or edge devices in production
* You've dealt with the reality of physical hardware in the field
* Strong Linux skills (our edge devices run on it)
* Experience with at least one device integration over industrial protocols (Modbus, MQTT, OPC-UA, or similar)
* An ownership mindset- you want to shape the platform, not just implement tickets
Even better if you have:
* Energy domain knowledge - you understand power, energy, phases, and how the grid works
* Experience with fleet management - OTA updates, device monitoring, remote debugging across many sites
* Familiarity with embedded Linux (Yocto, Buildroot, or similar) and containerized edge deployments
* Experience evaluating and selecting industrial edge hardware
* Experience with cloud IoT platforms (AWS IoT, Azure IoT Hub, or similar)
* Go, Rust, or Java in an IoT/systems context
* German language skills (our customers and partners are German)
Benefits
**Ownership
**This isn't a role where the architecture is decided and you fill in the blanks. The edge platform is greenfield - you'll co-design it from the ground up.
Real impact, fast Your code runs physical batteries that save real factories real money. You'll see results the same week you deploy.
Founding trajectory As FION grows, you grow with it - from hands-on builder to platform lead overseeing a fleet of batteries across the country. What takes 5 years at a large company, you'll have from day one.
Compensation
* 70,000 - 100,000 EUR annual gross salary (depending on experience)
* VSOP (virtual shares) - you participate in the company's success
* Berlin hybrid (remote from within Germany, possible for the right person)
Send us:
* Your CV or LinkedIn profile
* A few sentences on why this role interests you
* Optionally: a link to a project, repo, or writeup that shows how you think about technical problems
We review every application personally and get back to you within a week. No automated screening - you're writing to a person