Machine Learning Engineer, Trainline
£70-75k
Offers 2-for-1 share purchase plans
More information about location
Europe's leading rail ticketing platform
Posted today
Europe's leading rail ticketing platform
1001+ employees
Posted today
£70-75k
Offers 2-for-1 share purchase plans
More information about location
1001+ employees
Company mission
Trainline is proud to be Europe's leading rail and coach platform - a tech company with a mission to make train travel as smooth as possible to allow travellers to make greener travel choices.
Role
Who you are
- Have strong experience in Machine Learning with solid foundations in the ML lifecycle, evaluation methodologies, and statistical thinking
- Have hands-on experience with GenAI, Large Language Models, and NLP techniques, including RAG and agent-based systems
- Are proficient in Python and common ML libraries (e.g. PyTorch, scikit-learn, XGBoost, Pandas)
- Have experience deploying and operating ML or AI systems in production environments
- Understand ML Ops and DevOps principles (e.g. Docker, CI/CD, infrastructure as code)
- Have experience working with cloud infrastructure (preferably AWS)
- Take ownership of technical tasks and proactively drive solutions forward
What the job involves
- You’ll join a cross-functional team of Machine Learning Engineers and Data Engineers working on some of our most exciting GenAI initiatives
- We’re building agentic systems such as our Travel Assistant, an AI-powered experience that helps customers with refunds, journey updates, and ticket conditions and expanding into Voice AI agents to intelligently handle and redirect customer queries
- This is a team that combines strong ML fundamentals with cutting-edge LLM frameworks (LangGraph, LangChain), RAG architectures, MCP integrations, and production monitoring tools like Braintrust, all deployed on AWS
- We value ownership, curiosity, and thoughtful experimentation in a healthy, supportive environment
- This role is focused on designing, building, and operating LLM-powered and predictive ML systems in production
- You’ll work on agentic AI systems, including our Travel Assistant and Voice AI initiatives, while also contributing to more traditional ML services that the team owns
- If you’re passionate about GenAI, LLMs, NLP, and shipping robust ML systems end-to-end, this is an opportunity to work at the forefront of applied AI in a high-impact consumer platform
- Design and build LLM-powered agentic systems using frameworks such as LangGraph and LangChain
- Develop and optimise RAG pipelines, tool-using agents, and multi-step workflows with appropriate guardrails and validation
- Monitor and evaluate model and agent performance using appropriate ML metrics (e.g. precision, recall) and production monitoring tools
- Maintain and improve traditional ML models alongside newer GenAI capabilities
- Partner closely with stakeholders to frame problems, define success metrics, and deliver measurable business impact
- Take ownership of technical initiatives, driving delivery from ideation through to production and iteration
- Contribute to our wider AI & ML community through knowledge sharing, experimentation, and continuous learning
Salary benchmarks
Our take
Trainline make it super easy to book transport tickets. Its app is intuitive and well designed and its even pioneering paperless travel, allowing users to store their tickets in the app.
It's hyper-focused on customer experience and has a product culture of fast iteration to deliver great outcomes for customers. Its customers make 170,000 journeys a day and it sells 200 tickets a minute.
Its continuing to innovate to stay ahead, using machine learning to predict price movements and integrating with Siri and Google Assistant so people can buy tickets simply by speaking to their phone.
Steph
Company Specialist at Welcome to the Jungle
Insights
Company
Employee endorsements
Challenging work
"The complex nature of the market as we work with different suppliers is an amazing opportunity to create fluid solutions. A very well segmented..."
Company benefits
- Flexible working (60% min office attendance)
- Cycle to work scheme
- Discounted gym memberships through Wellhub
- Private Health and Dental Insurance
- Enhanced Pension (matched contributions)
- Income Protection
- Share Incentive Plan (buy one get one free)
- Learning budget
- Primary & Secondary Caregiver Leave
- Shared Parental Leave
- Enhanced sick pay
- Free Perkbox subscription
- Electric Vehicle Salary Sacrifice Scheme
- YellowNest - Subsidised Childcare Fees
- Work from Abroad
Company values
- Own It - We care about every customer, partner and journey
- Do Good - We make a positive impact
- Travel Together - We're one team
- Think Big - We are building the future of rail
Company HQ
Farringdon, London, UK
Articles
Leadership
Jody Ford
(CEO)Joined Trainline in 2020 as COO before becoming the CEO in 2021. Previously the Group CEO at Moonpig and Photobox and also spent over 10 years at eBay in various VP roles.
Lisa Hillier
(Chief People Officer)Previously the CPO at Gousto, The Restaurant Group, and Just Eat. They also spent over 6 years at Betfair as the Head of HR and Chief Human Resource Officer.
Mike Hyde
(Chief Technology Officer)Previously a Director of Data Science at Facebook and as a Director of Business Insights at Skype and Microsoft.
Sakshi Anand
(Chief Growth Officer)Joined Trainline in 2023 as the VP of Growth and President of UK before becoming the CGO in 2025. They are also the Founder of NeuStar Consulting.
People progressing
Gary joined in 2022 from Comparethemarket as Director of Engineering and was recently promoted to VP Engineering, reporting directly to CTO.
Joe joined in 2022 from Meta as Director of Data Science and was recently promoted to VP Data, reporting directly to CTO.
Ali joined in 2023 from Meta and was recently promoted to VP Product, reporting directly to CPO.
Diversity, Equity & Inclusion at Trainline
- 💚 Diversity drives us forward We know that having a diverse team is crucial to Trainline’s ongoing success. A team that is diverse in all forms – gender, ethnicity, sexuality, disability, nationality and diversity of thought are key to Trainline being an inclusive environment where every Trainliner can be their true self. We're committed to creating workplaces where everyone belongs, is celebrated and their differences are valued, creating an awesome employee and customer experience. 💚 Meet our Networks Our diversity networks are inclusive communities developed and led by Trainliners, with sponsorship and support from senior leaders. They're all about empowering and supporting underrepresented groups, by providing a safe space to talk, a place to come up with new ideas and a channel for voices to be heard. 🚀 Women in Leadership 💜 Gender Equality Network 🏳️🌈 Rainbow Train (LGBTQIA+) 🌻 Sunflower (accessibility) 🌍 Ethnic Diversity Network 🐣 Parent & Carers
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