Senior Engineer - Platform in London

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 highly rated mobile app, website, and B2B partner channels.

Now Europe’s number 1 downloaded rail app, with over 135 million monthly visits and £6.3 billion in annual ticket sales, we collaborate with 270+ rail and coach companies in over 40 countries. We want to create a world where travel is as simple, seamless, eco-friendly and affordable as it should be.

The Infrastructure Engineering and Tooling team, also known as Atlas, owns the ecosystem used to deploy, run and manage traffic across the Trainline platform. The team is currently building the next version of Trainline’s infrastructure platform, with a focus on reliability, quality, automation and secure, scalable delivery.

You will join a collaborative team made up of software engineers and platform engineers across a range of experience levels. The team works across technologies including Terraform, AWS, Node.js, C# and Python, but we do not expect you to know everything from day one. In this role, you will work closely with engineers, Tech Leads, Engineering Managers, Senior Principal and a Head of Engineering to improve our platform and deliver meaningful infrastructure change.

In this role as the Senior Platform Engineer, you will:

• Deliver complex improvements to Trainline’s engineering platforms, helping us build scalable, reliable and secure infrastructure that supports teams across the business.
• Implement and evolve infrastructure changes using Terraform, following existing module patterns while identifying opportunities to improve quality, maintainability and automation.
• Apply least-privilege and secure-by-default principles consistently across AWS accounts, helping ensure our infrastructure meets Trainline’s standards for security and operational excellence.
• Build or contribute to automation scripts and tooling using Node.js or Python, supporting faster, safer and more repeatable delivery.
• Support and review the work of mid-level engineers, sharing context, providing constructive feedback and helping others deliver confidently.
• Collaborate with Tech Leads, Delivery Managers and cross-functional stakeholders to shape delivery plans, achieve milestones and manage dependencies.
• Identify risks, blockers or quality concerns early, helping to unblock the team and keep delivery moving in a clear and sustainable way.
• Test, validate and deploy infrastructure changes through CI/CD pipelines, ensuring deliverables are robust, well-documented and production ready.

We’d love to hear from you if you have:

• Strong experience working with AWS services such as ECS, Lambda, IAM or CloudFront, with a solid understanding of operational and security best practice.
• Proven experience delivering infrastructure changes using Terraform, ideally in complex or large-scale cloud environments.
• The ability to work independently on complex platform engineering problems while bringing others along through clear communication and collaboration.
• Experience using Node.js or Python for automation, scripting or integration work, with a focus on practical, maintainable solutions.
• A good understanding of secure cloud design, including least privilege, account structure and service-to-service authentication approaches such as OIDC.
• Experience using AI tooling to support day-to-day engineering work, such as coding, code review, research or productivity improvements.
• A track record of delivering outcomes in agile, delivery-focused teams, with the confidence to raise risks, clarify priorities and support shared progress.
• Helpful experience with areas such as multi-account or multi-region AWS management, CDN, WAF, Git-based CI/CD pipelines or enterprise-scale AWS environments.

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 operating a hybrid model 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 every day, 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!