Today , Lonza is a global leader in life sciences operating across three continents. While we work in science, there’s no magic formula to how we do it. Our greatest scientific solution is talented people working together, devising ideas that help businesses to help people. In exchange, we let our people own their careers. Their ideas, big and small, genuinely improve the world. And that’s the kind of work we want to be part of .

We are looking for an Associate Principal Scientist (m/f/d) to join our Mammalian Cell Culture Development team in Visp . This role combines scientific leadership with hands- on laboratory work, driving upstream development activities and collaborating with cross- functional teams and customers to deliver high- quality bioprocessing solutions.

Key responsibilities:

• Lead, design, and execute complex upstream process development activities, including small scale studies (up to 10 L), ensuring compliance with quality and safety standards and generating the data and documentation required to support tech transfer to Pilot and GMP facilities.

• Act as subject matter expert (SME) for CHO cell culture, providing scientific guidance, troubleshooting support, and decision ‑ making for internal and external teams.

• Build and maintain strong customer relationships through transparent communication and scientific excellence.

• Design, optimize , and implement robust scale ‑ down and scale ‑ up models .

• Author and review high ‑ quality documentation, including study plans and development reports.

• Support training activities and promote knowledge ‑ sharing across teams.

• Contribute to continuous improvement, workflow optimization, and best ‑ practice implementation.

Key requirements :

• BSc with 7+ years or MSc with 5+ years of relevant industry experience in mammalian upstream process development.

• Hands- on expertise with CHO cell culture, including AMBR250 /AMBR15 , shake flasks, stirred tank bioreactors, and depth filtration.

• Strong understanding of scale up/ scale down principles, bioprocess troubleshooting, and tech transfer.

• Proven ability to plan, coordinate, and execute laboratory scale experiments in a dynamic, cross- functional environment.

• Excellent communication skills; technical English required .

• Willingness to support operations during weekends or public holidays several times per year.

• Strong team orientation, organizational skills, and problem solving mindset.

Every day, Lonza’s products and services have a positive impact on millions of people. For us, this is not only a great privilege, but also a great responsibility. How we achieve our business results is just as important as the achievements themselves. At Lonza, we respect and protect our people and our environment. Any success we achieve is no success at all if not achieved ethically.

People come to Lonza for the challenge and creativity of solving complex problems and developing new ideas in life sciences. In return, we offer the satisfaction that comes with improving lives all around the world. The satisfaction that comes with making a meaningful difference .