Senior Engineer – Applied Engineering & Testing

Castrol is one of the world’s leading lubricant brands, serving customers and consumers in the automotive, marine, industrial and energy sectors. Castrol brands are recognised globally for their premium quality and high performance, shaped by the company’s commitment to innovation and cutting-edge technology. With products sold in more than 150 countries, Castrol has helped keep things moving on roads and racetracks, air, sea, and space for over 125 years.

Whether you're just starting out or ready for your next big move, you're in the right place to explore an exciting career with Castrol.

About the Team

At Castrol, we don’t just make fluids, we help define the future of mobility, energy and digital infrastructure. The Advanced Electrification Testing (AET) team sits within Castrol’s Technology organisation and plays a critical role in supporting Research & Product Development by generating real-world performance data on lubricants, thermal management fluids and cooling technologies. Our mission is to understand how liquids perform inside the systems they are designed to protect and optimise, from electric vehicle batteries and ultra-fast chargers to high-performance data centres and advanced electronics.

As part of a major investment programme, Castrol’s Pangbourne Technology Centre is evolving into a centre of excellence for electrification and energy technologies. The team operates world-class testing facilities including battery cell, module and pack laboratories, high-voltage charging systems, immersion cooling tanks, data centre server environments and large-scale thermal management test rigs.

This is a team for engineers who are naturally curious. You'll work in an environment that combines the freedom of university-style research with the pace and impact of commercial product development. One day you may be investigating battery cooling performance, the next developing new testing methodologies for data centre technologies or semiconductor cooling systems.

You’ll join a highly collaborative group of engineers, technicians, graduates and researchers who are passionate about solving complex engineering challenges. We are looking for individuals who love understanding how things work, enjoy getting hands‑on with equipment, and want to help create the next generation of high-performance technologies.

As a Senior Engineer, you will lead research and development testing projects from concept through to final technical recommendations, working closely with internal stakeholders, technology experts and external partners.

• Leading end-to-end testing and engineering projects supporting Castrol's research and product development programmes.
• Designing, building, commissioning and operating advanced test rigs and experimental systems.
• Developing innovative testing methodologies for emerging technologies across electric vehicles, batteries, charging infrastructure and data centres.
• Designing experiments using statistical Design of Experiments (DoE) techniques and ensuring data quality and repeatability.
• Performing advanced data analysis and translating results into meaningful engineering insights and recommendations.
• Working hands‑on with high‑voltage systems, instrumentation, thermal management equipment and power electronics.
• Supporting the installation, operation and continuous improvement of testing facilities and equipment.
• Acting as a subject matter expert in one or more areas such as battery systems, thermal management, data centres, cooling technologies, power electronics or DC power systems.
• Collaborating with OEMs, technology partners and internal stakeholders to deliver co‑engineered solutions.
• Coaching and mentoring engineers, technicians,…