Job Description

Principal AI Engineer

London (hybrid working) 1 day per week in the London office, with flexibility depending on business needs and stakeholder engagement.

About the role

We're looking for a Principal AI Engineer to help establish, grow and shape AI capability across Railpen, providing technical leadership and expertise as we develop our approach to AI.

This is a newly created role and a key appointment within our Technology team. You'll play a leading role in identifying where AI can create genuine value, design practical solutions and helping us build the foundations needed to scale AI effectively and responsibly across the organisation.

You'll bring together a strong software engineering background with hands-on AI expertise, working closely with colleagues across Technology and the wider business to turn opportunities into real-world outcomes. Whether that's designing new AI-powered solutions, shaping technical standards, evaluating emerging

technologies or helping others understand what's possible, you'll be at the centre of how AI capability is developed and adopted across Railpen.

This role requires someone who enjoys combining deep technical expertise with strong stakeholder engagement. You'll be comfortable engaging with senior leaders, translating complex concepts into clear language and helping build confidence in the use of AI across the business.

To learn more about Railpen including our values, culture and purpose, visit our careers page here.

What you’ll be doing

• Leading the design, development and delivery of AI solutions that solve genuine business problems.
• Building scalable, secure and maintainable AI applications using modern engineering practices.
• Driving the adoption of AI across the organisation by helping teams identify and realise opportunities.
• Working closely with architects, engineers, product teams and business stakeholders to translate requirements into practical solutions.
• Evaluating emerging AI technologies and recommending where they can create value.
• Defining engineering standards, best practice and reusable approaches for AI development across Railpen.
• Ensuring AI solutions are developed responsibly, with appropriate governance, security and risk considerations.
• Acting as a trusted technical expert, providing guidance and support to both technical and non-technical audiences.
• Helping to develop AI capability across the wider technology function through coaching, mentoring and knowledge sharing.

What we’re looking for

Essential

• Significant experience in software engineering, including providing technical leadership and designing and delivering enterprise-grade applications.
• At least two years of hands-on commercial AI engineering experience gained as part of your day-to-day role.
• Proven experience building, deploying and supporting AI solutions in a production environment.
• Strong experience with modern AI technologies, including Large Language Models (LLMs) and generative AI solutions.
• Excellent programming skills, ideally including Python and experience working with cloud-based platforms.
• Strong understanding of software engineering principles, architecture, testing and deployment practices.
• Experience translating complex technical concepts into language that senior stakeholders and non-technical audiences can understand.
• Excellent communication and stakeholder management skills.
• A proactive and curious mindset, with a passion for staying ahead of developments in the rapidly evolving AI landscape.

Desirable

• Experience with Azure AI services, Azure OpenAI, AI Foundry or similar platforms.
• Experience designing and implementing Retrieval-Augmented Generation (RAG) solutions.
• Experience with agentic AI workflows and orchestration frameworks.
• Experience working in a regulated environment such as financial services, pensions, insurance or banking.
• Experience establishing AI standards, governance frameworks or best practice within an organisation.
• Previous experience mentoring engineers or providing technical leadership across delivery teams.

Why is this role exciting now?

AI is creating new opportunities across every industry, and we're committed to building the capability needed to make a meaningful impact at Railpen. This role will play a key part in helping us realise that potential.

This role offers the chance to join at a pivotal stage of our journey. Rather than inheriting a mature AI function, you'll help shape and build it. You'll have the opportunity to influence technology decisions, establish new ways of working and play a key role in defining how AI is adopted across the organisation.

If you're looking for a role where you can combine technical excellence with genuine influence and impact, this is an opportunity to help shape the future direction of Railpen's AI capability.

What you’ll get in return

• A competitive salary (depending on experience) plus generous annual bonus plan
• 28 days annual leave plus bank holidays
• We provide membership of the Railways Pension Scheme, a Defined Benefit arrangement under which you get a pension for life and a lump sum when you retire, based on your length of service and pay
• 4x Life Assurance cover
• We support hybrid and flexible working along with very generous family leave including 12 months full pay maternity leave and 6 months full pay paternity leave
• Take a look at the full range of benefits available to support you, click here

Next steps

If you’re excited by the opportunity to make a meaningful contribution and grow your career with us, we encourage you to apply by 23rd October 2026.

Inclusion at Railpen

At Railpen, diversity, equity and inclusion are core to who we are. We’re committed to creating a workplace where everyone feels respected, supported and able to thrive. Our mission to secure a better future for our members is strengthened by the different perspectives and experiences our people bring.

We are transparent about our gender pay gap and are actively committed to addressing it through fair and inclusive recruitment, progression and reward practices.

We respect and support individuals’ pronouns and encourage colleagues to share them if they feel comfortable to do so.

We’re proud to be an equal opportunity employer. We welcome applicants from all backgrounds and do not discriminate on the basis of age, ethnicity, religion, sex, sexual orientation, gender identity, disability, neurodiversity, or any other protected characteristic. If you need adjustments during the recruitment process, just let us know.