About this role
We’re building the UK's next generation engineering powerhouse, providing critical technology that strengthens national security and resilience. We specialise in turning advances in sensing, AI, and communications into operational capability for the edge, where connectivity may be degraded or denied. Our work focuses on accelerating the deployment of technology, improving decision-making for frontline teams, and protecting people and critical assets in demanding environments. Headquartered in Bristol, Rowden employs around 200 people and operates over 20,000 square feet of engineering and manufacturing facilities. We have a growing international footprint and are one of Europe’s fastest-growing engineering businesses.
About the role
As part of this journey, we are growing our ML team rapidly. The team works end-to-end, from applied R&D to deployment, across deep learning, data engineering, large models and LLM/agentic systems. Our work spans R&D contracts with the MOD and wider government, deploying ML onto edge and embedded hardware, and the assurance and testing that shows those systems can be trusted. As a Principal ML Engineer, you will be a technical authority on our most important ML work.
This is a principal individual contributor role: you will take the technical lead on key projects, contribute technical expertise to bids, and represent Rowden’s ML capability with customers and partners, including at international exercises a few times a year. This is a hands-on engineering role working closely with software, hardware, systems and RF engineers, and with our ML craft and technical leads. You will report to the Head of ML.
No prior defence experience is required. We’re interested in people who’ve built and deployed AI systems in demanding environments and are passionate about delivering tangible value to end users, whatever the sector. While this role offers hybrid working options, it requires a minimum of 3 days per week on-site at our Bristol HQ, with occasional travel to customer sites and international travel a few times a year. Candidates must be eligible for Developed Vetting (DV) clearance.
More information about security clearance is available here: https://www.gov.uk/government/publications/united-kingdom-security-vetting-clearance-levels Salary For senior roles, compensation is tailored to the scope of the role and the specific experience a candidate brings. Because that can vary significantly, we do not always publish a fixed salary band. We will, however, discuss compensation openly at the first stage of the process and can share an indicative range before either side invests significant time.
- Technical authority: take technical ownership of our most demanding ML projects, set the approach, and make the decisions that matter.
- Stay hands-on at depth: design, build, train and debug yourself.
- This is a senior engineering role, not an advisory one.
- Train and adapt large models: lead our large model work, including pre-training, fine-tuning, distributed training and evaluation at scale.
- LLMs and agentic systems: bring practical expertise to projects across the team that build on LLMs and agents, with an eye on latency, cost and reliability in constrained settings.
- From data to the edge: make sure our solutions work end-to-end, from data pipelines and training infrastructure through to deployment on edge hardware, with evaluation that tells us what a model actually does.
- Represent Rowden externally: lead our technical presence at exercises, trials and customer engagements, and contribute technical expertise to bid writing.
- Raise the bar: set what good looks like with our craft and technical leads, and mentor engineers through reviews, pairing and example.