Trainline is seeking a Machine Learning Engineer to join us in building the future of rail travel. In this role, you will focus on designing, building, and operating LLM-powered and predictive ML systems in production, working on agentic AI initiatives like our Travel Assistant and Voice AI alongside traditional ML services.
What You'll Do
- 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 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.
What We're Looking For
- Strong experience in Machine Learning with solid foundations in the ML lifecycle, evaluation methodologies, and statistical thinking.
- Hands-on experience with GenAI, Large Language Models, and NLP techniques, including RAG and agent-based systems.
- Proficient in Python and common ML libraries (e.g. PyTorch, scikit-learn, XGBoost, Pandas).
- Experience deploying and operating ML or AI systems in production environments.
- Understanding of ML Ops and DevOps principles (e.g. Docker, CI/CD, infrastructure as code).
- Experience working with cloud infrastructure, preferably AWS.
- A proactive approach to taking ownership of technical tasks and driving solutions forward.
Technical Stack
- Languages & Libraries: Python, PyTorch, scikit-learn, XGBoost, Pandas, LangGraph, LangChain
- Infrastructure & Tools: AWS, Docker
Team & Environment
You’ll join a cross-functional team of Machine Learning Engineers and Data Engineers working on some of our most exciting GenAI initiatives.
Benefits & Compensation
- Private healthcare & dental insurance
- Generous work from abroad policy
- 2-for-1 share purchase plans
- EV Scheme
- Extra festive time off
- Excellent family-friendly benefits
- Personal learning budgets
- Regular learning days
Work Mode
This is a hybrid role, open to candidates based in London, Paris, Barcelona, Milan, Edinburgh, or Madrid.
Trainline is an equal opportunity employer.
