Senior Process Engieer

ABOUT US tozero is Europe’s leading deep-tech startup specializing in the recycling of lithium-ion batteries. Committed to accelerating decarbonization and transforming the material life cycle, we’re actively crafting sustainable recycling solutions for a cleaner and more innovative future. WHAT WE'RE LOOKING FOR We are looking for a Senior Process Engineer to take a leading technical role in the design, scale-up, commissioning and ramp up of our battery recycling processes. This role sits at the intersection of technology development, process engineering, and industrial scale-up. You will translate experimental and operational data into robust process designs, challenge engineering assumptions, and ensure that our future plants are built on solid fundamentals. Your focus will be on the processes that matter most to our technology — graphite and lithium extraction. By working closely with R&D, Operations and external engineering partners, you will actively lead and engage in activities associated with: a) engineering design; b) commissioning and ramp up; c) process development. We are looking for someone who is comfortable working in a production environment, but who can also take a step back and understand what the data is telling us, and engineer the process we need at different scales. WHAT YOU CAN EXPECT Must Have's: 1. Future Plant Design & Scale-up ● Own key process design activities for our next-generation plants. ● Develop and review PFDs, P&IDs, mass and energy balances, process descriptions and equipment specifications for future capacity expansions. ● Translate pilot and industrial operating data into reliable engineering design criteria and scale-up assumptions. ● Perform process calculations and equipment sizing to ensure our future plants are designed based on validated engineering data rather than theoretical assumptions alone. 2. Targeted Process Expertise & Optimization ● Become a technical reference for some of our most critical process steps. ● Apply strong chemical engineering fundamentals to the optimization of graphite and lithium extraction and post-processing. ● Identify the parameters controlling yield, purity and process stability and translate these insights into concrete process improvements. ● Work closely with R&D and Operations while maintaining a strong focus on process performance and technology development rather than daily troubleshooting. 3. Data Analysis & Process Modeling ● Turn plant data into engineering decisions. ● Evaluate operational and experimental data, build and validate mass balances and process models, and identify gaps between expected and actual process performance. ● Define what data needs to be collected to support future scale-up decisions. ● Technically guide data analysts and other engineering functions to ensure that models and analytics remain grounded in physical and chemical reality. ● Translate analysis into clear recommendations for process upgrades and future