Principal Scientist, Process Engineering Full-time

Principal Scientist, Process Engineering

At Bristol Myers Squibb, our employees often ask, “Who are you working for?”—a question that fuels collaboration, accountability, and urgency in our work. Our purpose-driven culture inspires us to discover, develop, and deliver innovative medicines to prevail over serious diseases. We offer uniquely interesting and meaningful work, opportunities for growth, and a supportive environment that values inclusion, wellbeing, flexibility, and comprehensive benefits. This is work that transforms the lives of patients, and the careers of those who do it.

Your work will reach patients. Let's talk about how.

Every medicine that makes it to a patient starts as a complex chemistry problem. Someone has to take a process that works seamlessly in a lab flask and make it work safely, reliably and at scale – in a manufacturing facility.

That someone could be you.

At Bristol Myers Squibb, we're looking for a Process Engineer to join our Chemical Process Development (CPD) team in Moreton, UK. CPD delivers clinical supplies and process development for all synthetic and anti-body drug conjugate (ADC) drug substances at BMS. This is a role where your engineering depth and your interpersonal skills will directly shape how – and how quickly – our clinical work reaches the patients who need them.

So, what does the role actually look like day-to-day?

You'll sit at the dynamic intersection between our internal science teams and the external Contract Development and Manufacturing Organisations (CDMOs) who bring our processes to life at scale.

On any given week, you might be:

• Reviewing a batch record for a hazardous chemistry campaign, making sure everything from safety and quality controls to process intent is technically accurate and operationally feasible before it goes near a plant
• Walking a CDMO facility, either virtually or in person, assessing whether their equipment and capabilities are the right fit and if not, articulating exactly why and what needs to change
• Troubleshooting a manufacturing issue, drawing on your engineering fundamentals and collaboration skillset to find the root cause and get things back on track
• Presenting risk assessments and recommendations to leadership, translating complex technical realities into clear, actionable decisions
• Building strong relationships with CDMO partners across the world – to improve how we work together and so that when things get difficult (and sometimes they will), you already have the trust in the room

What's in it for you?

Let's be direct about the real value this role offers you as a professional:

• You'll work across the full range of chemical engineering unit operations — reaction, crystallisation, distillation, extraction, filtration, drying, and milling — applied to pharmaceutical small molecule/ADC scale-up.
• Real influence across teams and organisations This role demands – and rewards – the ability to drive technical negotiations, influence cross-functional teams, and build trusted working relationships with external partners. For the right person, this is where your interpersonal skills become as professionally valuable as your engineering ones.
• A global role with a local base You'll be based at our Moreton, UK site but working closely with colleagues across the Atlantic – including your direct line manager in the US – and with CDMOs around the world. With up to 50% remote working available, you get flexibility without losing the connection and collaboration that makes this kind of work rewarding.
• Variety beyond the desk Up to 20% international travel means you'll be on-site at CDMOs and in facilities.
• A platform to grow and give back BMS actively values mentorship and knowledge-sharing. Whether it's developing colleagues, contributing to communities of practice, or helping shape how the function works – this is a role where building others up is part of the job, not an afterthought.

Is this you?

• You'll bring a B.Eng. or M.Eng. in Chemical Engineering and at least 10–15 years of industrial manufacturing experience – ideally in pharmaceutical drug substance manufacturing and GMP environments. Experience in specialty chemical or petrochemical industries is also acceptable.
• You know how to read a lab protocol and visualise how it will operate in a manufacturing environment.
• You can spot scale-up risk before it becomes a manufacturing incident.
• You have a strong grounding in chemical engineering fundamentals across reaction, crystallisation, distillation, extraction, filtration, drying, and milling
• But just as importantly: you communicate clearly, you adapt your approach to the audience and the stakes, and you're comfortable managing complexity across multiple workstreams and stakeholders at once.
• Experience in lab-based small molecule development? Useful, but not essential.

Please note: This position requires work within facilities handling hazardous chemical agents, which, if improperly handled, may have the potential to affect employee health, including reproductive function and/or embryo/fetal development.

Why BMS, why now?

BMS is a company that has approved treatments that have genuinely changed what's possible in oncology, immunology, cardiovascular disease, and beyond. Our pipeline continues to grow — and the work of our Chemical Process Development team is central to keeping it moving.

When you get this right, patients get their medicine sooner. That's the job.

Ready to apply? We'd love to hear from you.