Machine Learning Engineer

Trainline; Greater London; Hybrid; GBP 60,000 - 90,000; Full time

Benefits offered by this job

Private healthcare

Dental insurance

Share purchase plans

EV scheme

Work-from-abroad policy

Festive time off

Family-friendly benefits

Job summary

Trainline is seeking a Machine Learning Engineer to join a high-performing, deeply technical team that tackles complex problems by uniting Trainline’s data with cutting-edge algorithms to support sustainability initiatives.

You will collaborate with data scientists, software engineers and product managers to design, deploy and monitor ML models at scale in production environments, using Python, Spark and ML tooling.

Qualifications

• Advanced degree in CS, math, statistics or related field.
• Proficiency with Python and Pandas/NumPy/Scikit-learn.
• Experience productionising ML models and AI solutions.
• Experience with Spark.
• Familiarity with CI/CD and DevOps practices.

Responsibilities

• Collaborate in cross-functional teams with data scientists, software, data and product managers.
• Design and deploy ML models and AI solutions at scale with measurable impact.
• Own end-to-end ML lifecycle: data exploration, feature engineering, evaluation, deployment.
• Partner with stakeholders to create data products leveraging Trainline’s datasets and advanced algorithms.
• Create tools and frameworks to accelerate ML product delivery and improve workflows.
• Take an active role in the AI/ML community and foster a culture of learning and experimentation.

Skills

Python

Pandas

NumPy

Scikit-learn

Spark

Docker

Terraform

MLflow

CI/CD

Data wrangling

Statistical methods

Communication

Education

Advanced degree in Computer Science/Math/Statistics

Tools

MLflow

Terraform

Job description

Overview

We are champions of rail, inspired to build a greener, more sustainable future of travel. Trainline enables millions of travellers to find and book the best value tickets across carriers, fares, and journey options through our mobile app, website, and B2B partner channels.

Today, we are a FTSE 250 company with a diverse team of over 1,000 Trainliners from 50+ nationalities, based across multiple cities in Europe. We are focused on growth in the UK and Europe and are looking for talented people to join us on this high-speed journey.

Machine learning and AI are at the core of how Trainline transforms travel. Our ML models and AI solutions power critical aspects of our platform, including advanced search and recommendations, pricing and routing optimisations, personalised user experiences, data-driven marketing systems, and AI agents improving customer support. Our machine learning teams own the complete delivery lifecycle from ideation to production and work with stakeholders to expand the impact of ML and AI throughout Trainline.

About the Role

We are looking for Machine Learning Engineers to join our team to shape the future of train travel. You will join a high-performing, deeply technical community of Machine Learning Engineers, Data Scientists and Data Engineers to tackle complex problems by combining Trainline’s datasets with cutting edge algorithms. Our goal is to create impactful solutions that support Trainline’s sustainability objectives.

You will be in an environment where learning and development is a top priority and will have the opportunity to work with ML & AI enthusiasts on large-scale production systems delivering products that make a difference to millions of customers.

Responsibilities

• Work in cross-functional teams combining data scientists, software, data and machine learning engineers, and product managers
• Design and deliver machine learning models and AI solutions at scale that drive measurable impact for Trainline
• 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
• Partner with stakeholders to propose innovative data products that leverage Trainline’s datasets and state-of-the-art algorithms
• Create tools and frameworks that accelerate ML & AI product delivery and improve workflows
• Take an active part in the AI and ML community and foster a culture of rigorous learning and experimentation

Qualifications

• Advanced degree in Computer Science, Mathematics, Statistics or a related quantitative field
• Proficiency with Python and open-source data libraries (e.g., Pandas, NumPy, Scikit-learn)
• Experience productionising machine learning models and AI solutions
• Expertise in predictive modelling, classification, regression, optimisation, NLP algorithms or recommendation systems
• Experience with Spark
• Knowledge of DevOps technologies such as Docker and Terraform and ML Ops practices and platforms like MLflow
• Experience with agile delivery methodologies and CI/CD processes
• Understanding of data extraction, manipulation and feature engineering techniques
• Familiarity with statistical methodologies
• Strong communication skills

Nice to have

• Experience in the transport industry and/or geographic information systems (GIS)
• Experience with cloud infrastructure
• Experience with Large Language Models (fine-tuning, RAG, agents)
• Experience with graph technology and/or algorithms

More information

We offer generous benefits including private healthcare and dental insurance, a work-from-abroad policy, share purchase plans, an EV scheme to reduce carbon emissions, extra festive time off, and 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. A 28-day work-from-abroad policy is available.

Our values guide everything we do: Think Big, Own It, Travel Together, and Do Good. We are committed to diversity and inclusion and to creating an inclusive workplace where everyone belongs and differences are valued.

Interested in finding out more about what it’s like to work at Trainline? Check us out on LinkedIn, Instagram and Glassdoor.