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

We are looking for a Principal Software Engineer to build the Internal Developer Platform that our engineering teams depend on - a platform built from the ground up for agentic engineering. Our software teams work on hard problems under tight deadlines. Your job is to make sure the platform underneath them is not one of those problems.

Working within the Platforms team, you will architect and own the tooling, infrastructure, workflows, and components that Rowden’s developers build on. That means repeatable development environments, paved paths that are faster than the alternatives, and platform services that teams adopt because they want to, not because they have to.

You will lead the implementation of agentic AI and passionately advocate for its use: rolling out coding agents, embedding them into CI/CD and day-to-day development, and building the harnesses and infrastructure that let them run securely, efficiently, and transparently. You will track new developer tooling and agentic AI closely, adopt what works before most teams have heard of it, and enjoy convincing others to do the same. This role gives you a whole engineering organisation to do that for.

This is some of the highest-impact engineering in the company. It is not a delivery role. You will not be assigned to customer projects, and you will not review delivery PRs. Your users are Rowden engineers, and the platform is the product.

Candidates must be eligible for SC 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.

As a Principal Software Engineer at Rowden, you will:

Build the Internal Developer Platform: design, build, and run the platform that Rowden's software teams and their coding agents depend on to write, test, ship, and operate code.
Own software engineering infrastructure and workflows end-to-end: source control, CI/CD, artefact management, secrets, and the environments our software runs in.
Champion new tooling and best practice: track what the best engineering organisations are doing, evaluate it rigorously, and bring in whatever earns its place.
Raise standards through influence: set technical direction and standards across teams you do not manage, by building things that people choose to use.
Lead the implementation of agentic AI: roll out coding agents across engineering workflows and own how and where they're used.
Advocate for agentic engineering across the business: run evaluations, evidence the benefits, and train teams on effective use.
Build the infrastructure that makes agents trustworthy: sandboxing, permissioning, audit logging, and observability so that what an agent did is efficient, secure, and fully transparent to the engineer who has to stand behind it.
Create repeatable development environments: make local, cloud, and target-representative environments reproducible, quick to stand up, and identical for every engineer.

We don't expect anyone to be a 10/10 in every area, and you don't need to tick every single bullet point to apply. What follows is a list of the skills and experience that we think matter most for this role. Different strengths are welcome.

Substantial experience as a principal or staff software engineer.
Demonstrable experience building developer platforms, internal tooling, and paved paths used by engineering team.
Hands-on experience implementing agentic AI in real engineering workflows (beyond individual experimentation).
Experience designing the guardrails around agentic AI: sandboxing, permissioning, audit logging, or observability for tools operating with elevated access.
Deep, hands-on experience of CI/CD, infrastructure as code, containers, and Kubernetes.
Experience of building and deploying reproducible development environments.
A track record of driving adoption by persuasion and good product decisions, not mandate.
Clear written communication, including documentation that engineers actually read.

About you

You treat the platform as a product and your colleagues as customers, and you measure yourself on their throughput rather than your own.
You notice friction that everyone else has learned to live with, and you fix it.
You're a genuine advocate for agentic engineering. You make the case for it with evidence, help teams adopt it well, and are honest about where it isn't the right tool.
You are opinionated about tooling and you change your mind when the evidence changes.
You are comfortable owning something long-lived rather than moving between projects.
You can tell the difference between a genuinely better tool and a fashionable one.
You are honest about trade-offs, including the ones in your own work.

No prior defence experience is required. We're interested in people who've built and run developer platforms in demanding environments, wherever that was.

Rowden

Principal Software Engineer - Platforms

About the Job

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About the Company

Rowden

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