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. 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. 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 plant designs. 4. Commissioning & Process Validation ● Make sure what we designed actually works. ● Participate in FATs/SATs, commissioning activities and process performance validation for new equipment and plant expansions. ● Develop acceptance and process validation criteria based on the original design intent. ● Evaluate commissioning and operational data to confirm that installed systems achieve their calculated performance targets. ● Work closely with Operations during handover while ensuring clear ownership transfers once the process meets its design criteria. 5. Operational Readiness, Process Safety & SOPs ● Design processes that can be operated safely and consistently. ● Translate process design and engineering intent into clear Standard Operating Procedures (SOPs), operating envelopes and process documentation. ● Participate actively in HAZOPs, LOPAs, and other process safety reviews, ensuring that process risks are identified and addressed during design rather than after installation. ● Support Operations in understanding the design basis and critical process parameters of newly commissioned systems. Nice-to-have's: Vendor & EPC Coordination ● Represent tozero's process requirements with external engineering partners and equipment suppliers. ● Prepare and review technical specifications, vendor proposals and engineering documentation. ● Challenge unsupported assumptions, identify over-engineered solutions and ensure equipment is correctly sized for our process. ● Support technical bid evaluations and equipment selection, balancing process performance, CAPEX, operability and scalability. ● Act as a strong technical counterpart to EPCs, engineering contractors and equipment vendors throughout project execution. 4. The role requires regular on-site presence in Gendorf, with an expectation of approximately 2 days per week on average . Depending on project needs and plant activities, some weeks may require more on-site presence, while others may require less.