Machine Learning Engineer

Salary: £65,000 - 105,000 per year

Requirements:

• We require an advanced degree in Computer Science, Mathematics, Statistics, or a similar quantitative discipline.
• We are looking for proficiency with Python, including open-source data libraries such as Pandas, Numpy, and Scikit-learn.
• We need experience productionising machine learning models and/or AI solutions.
• We are seeking expertise in one of predictive modelling, classification, regression, optimisation, NLP algorithms, or recommendation systems.
• We require experience with Spark.
• We value knowledge of DevOps technologies such as Docker and Terraform, and MLOps practices and platforms like MLflow.
• We look for experience with agile delivery methodologies and CI/CD processes and tools.
• We need a broad understanding of data extraction, data manipulation, and feature engineering techniques.
• We expect familiarity with statistical methodologies.
• We require great communication skills.
• Nice to have: experience with the transport industry and/or geographical information systems (GIS).
• Nice to have: experience with cloud infrastructure.
• Nice to have: experience with Large Language Models, including fine tuning, RAG, and agents.
• Nice to have: experience with graph technology and/or algorithms.

Responsibilities:

• We work in cross-functional teams combining data scientists, software, data and machine learning engineers, and product managers.
• We design and deliver machine learning models and/or AI solutions at scale that drive measurable impact for Trainline.
• We own the full end-to-end machine learning delivery lifecycle, including data exploration, feature engineering, model selection and tuning, offline and online evaluation, deployments, and maintenance.
• We partner with stakeholders to propose innovative data products that leverage our extensive datasets and state-of-the-art algorithms.
• We create the tools, frameworks, and libraries that accelerate our ML & AI product delivery and improve our workflows.
• We take an active part in our AI and ML community and foster a culture of rigorous learning and experimentation.

Technologies:

• AI
• CI/CD
• Cloud
• DevOps
• Docker
• GIS
• Machine Learning
• MLflow
• MLOps
• Mobile
• Python
• RAG
• Spark
• Terraform
• numpy
• pandas
• Support
• Marketing
• Web

More:

We are Trainline, champions of rail, building a greener, more sustainable future of travel. We help millions of travellers find and book the best value tickets across carriers, fares, and journey options through our highly rated mobile app, website, and B2B partner channels. We are now Europes number 1 downloaded rail app, with over 135 million monthly visits and 6.3 billion in annual ticket sales, working with 270+ rail and coach companies in over 40 countries. We are a FTSE 250 company with over 1,000 Trainliners from 50+ nationalities across London, Paris, Barcelona, Milan, Edinburgh, and Madrid. We offer fantastic perks including private healthcare and dental insurance, a generous work-from-abroad policy, 2-for-1 share purchase plans, an EV scheme, extra festive time off, and excellent family-friendly benefits. We prioritise career growth with clear career paths, transparent pay bands, personal learning budgets, and regular learning days. We operate a hybrid model and ask Trainliners to work from the office a minimum of 60% of their time over a 12-week period, with a 28-day work-from-abroad policy. Our values are Think Big, Own It, Travel Together, and Do Good, and we are committed to creating inclusive places to work where everyone belongs and differences are valued and celebrated.

last updated 35 week of 2026