Optimization and Forecast Engineer - Energy Systems (f/m/d)

About FION European industry is losing competitiveness because electricity here is more expensive and more volatile than in the US or China. The reason: renewables fluctuate strongly, factories consume constantly. We close that gap. FION plans and installs the right battery system for an industrial site and runs it with AI in real time against tariffs and markets. The software that dimensions, controls and monitors those systems is our own, and it runs end to end: ML and optimization in the cloud, data streaming and control, and the edge device at the customer site. The result for the customer: significantly lower energy costs and measurable CO2 savings. We earn trust by delivering systems and operating them transparently. We already work with more than 20 factories across industries such as plastics, automotive and food processing, and we are backed by early-stage investors. We're looking for an engineer with deep experience in time-series forecasting and mathematical optimization to join us as an early hire. You'll work on the forecasting and optimization core of our platform: the models that forecast industrial electricity consumption and PV generation, and the optimization that decides how each battery operates and trades against tariffs and markets within physical and grid constraints. This is a startup role: you should be comfortable switching between strategic thinking and hands-on work. You'll work directly with the CTO, one of the co-founders. Tasks Forecasting models Develop and improve time-series forecasting models for industrial electricity consumption, PV generation, and other energy-relevant signals, and extend them with probabilistic outputs. Evaluate forecast quality on noisy, incomplete, and non-stationary industrial data, including its actual operational and economic impact. Battery dispatch optimization Develop and improve the optimization models that schedule battery dispatch across peak shaving, self-consumption, spot market trading and flexibi