Trainline - Principal Data Engineer

• Act as a technical authority across multiple teams, setting standards and patterns for data and ML‑adjacent infrastructure • Embed with ML teams to design, build and evolve data platforms supporting AI and ML workloads • Influence technical direction without direct line management responsibility • Partner with Data Engineering teams outside of ML to build a community and share best practices and findings across all areas • Identify systemic issues and proactively drive improvements across the data ecosystem • Look for short term and strategic opportunities to enhance core platforms with new self-serve enablement features for ML and DE • Your typical day may include: • Partnering with MLEs to design data pipelines supporting model training, inference and experimentation • Designing and reviewing architectures for ML‑ready data platforms • Building and optimising data pipelines using SQL, Spark or Ray and Python • Defining best practices for orchestration using Airflow or similar tools • Supporting API‑driven and event‑based data access patterns • Working with AWS infrastructure such as ECS, vector databases and Bedrock APIs • Reviewing designs and code across teams to raise quality and consistency • Coaching engineers through pairing, design reviews and informal mentoring • Collaborating on innovative AI‑powered product features such as the Travel Assistant • We'd love to hear from you if you have...🔍 • Extensive experience as a Senior, Staff or Principal Data Engineer operating across teams • Deep expertise in SQL and Python, with strong experience in Spark or similar tooling. • Strong understanding of orchestration tools such as Apache Airflow • Experience designing data platforms for ML and AI workloads • A track record of introducing new technologies and practices, and handling ambiguity and multiple stakeholders. • Hands‑on experience with AWS infrastructure (e.g. ECS, IAM, data storage, compute) • Familiarity with vector databases and modern AI/ML APIs (e.g. Bedrock) • Experience working closely with Machine Learning Engineers in production environments • Strong system design skills and the ability to influence through technical leadership • More information: • Enjoy fantastic perks like private healthcare & dental insurance, a generous work from abroad policy, 2-for-1 share purchase plans, an EV Scheme to further reduce carbon emissions, 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. Jump on board and supercharge your career from day one! • We're operate a hybrid model to work and ask that Trainliners work from the office a minimum of 60% of their time over a 12-week period. We also have a 28-day Work from Abroad policy. • Our values represent the things that matter most to us and what we live and breathe everyday, in everything we do: • 💭 Think Big - We're building the future of rail • ✔️ Own It - We focus on every customer, partner and journey • 🤝  Travel Together - We're one team • ♻️ Do Good - We make a positive impact • We know that having a diverse team makes us better and helps us succeed. And we mean all forms of diversity - gender, ethnicity, sexuality, disability, nationality and diversity of thought. That's why we're committed to creating inclusive places to work, where everyone belongs and differences are valued and celebrated. • Interested in finding out more about what it's like to work at Trainline? Why not check us out on LinkedIn, Instagram and Glassdoor!