Senior Backend Engineer - Developer Experience

About us

At Trainline, our purpose is to empower greener travel choices, connecting people and places. https://www.thetrainline.com/terms/sustainability-faqs 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. 

Great journeys start with Trainline 🚄 

We’re Europe’s leading independent rail platform, helping millions of travellers find and book the best-value rail and coach journeys across our app, website and partner channels.

Our job is to make the green travel choice the best choice. By building a better train travel experience, we help more people choose rail - creating a positive impact for customers, our business and the planet.

We’re a team of more than 1,000 Trainliners from over 50 nationalities, working across London, Paris, Barcelona, Milan, Edinburgh and Madrid. Now is a brilliant time to join us and help shape the future of travel.

INTRODUCING THE TRAINLINE CLOUD NATIVE DEVELOPER EXPERIENCE TEAM

At Trainline, we're evolving the platform that powers millions of journeys across Europe. As part of our Cloud Native Acceleration Programme, we're modernising our backend services to create a more scalable, resilient and efficient engineering platform. This programme is about more than migrating workloads. It's an opportunity to redefine how .NET services are built, deployed and operated, helping teams deliver faster while improving reliability and reducing operational complexity.

As a Senior C# Engineer, you'll play a key role in shaping our cloud-native engineering standards. Working closely with Platform Engineering, Infrastructure, Security and product development teams, you'll modernise existing services, build reusable patterns and develop automation that accelerates engineering across the organisation. Your work will have a lasting impact on both the developer experience and the resilience of our platform.

Success in this role is measured not only by modernising services, but by raising engineering capability across Trainline through reusable tooling, technical leadership, collaboration and the adoption of cloud-native engineering practices and by the ability to collaborate across the organisation.

IN THIS ROLE AS THE SENIOR C# ENGINEER, YOU WILL...

- Modernise existing .NET services by containerising applications for Amazon ECS, removing legacy infrastructure dependencies and optimising services for cloud-native operation.

- Design and build resilient distributed systems by improving health checks, fault tolerance, observability and runtime behaviour to enhance service reliability and reduce operational incidents.

- Define and evolve the .NET migrations by creating reusable service templates, engineering standards and best practices covering dependency injection, configuration, logging, monitoring and deployment.

- Develop automation and AI-assisted tooling that accelerates cloud migration by analysing existing services, identifying modernisation opportunities and generating infrastructure and deployment scaffolding.

- Optimise containerised workloads to improve performance, resource utilisation and scalability, helping teams deliver efficient, cost-effective services at scale.

- Partner with engineering teams across Trainline to drive adoption of cloud-native engineering practices, influence technical direction and build consensus around modernisation approaches that enable successful service migrations.

- Contribute to the continuous improvement of CI/CD pipelines and deployment processes, enabling faster, safer and more consistent software delivery.

- Champion cloud-native engineering through technical leadership, documentation, design reviews, demos, mentoring and engineering community engagement, helping teams adopt consistent engineering practices with confidence.

WE'D LOVE TO HEAR FROM YOU IF YOU HAVE...

CORE SKILLS

- Strong professional experience developing applications with C# and .NET, alongside a solid understanding of software engineering principles and modern backend architecture.

- A good understanding of distributed systems, including resilience patterns, observability, scalability and performance optimisation.

- Experience designing reusable engineering patterns, frameworks or shared libraries that improve consistency and developer experience across multiple teams.

- Strong collaboration and communication skills, with the ability to work effectively across engineering teams and influence technical decisions through partnership and expertise.

- A continuous learning mindset and a passion for improving engineering practices, modernising legacy systems and delivering measurable business impact.

INFRA AND CLOUD NATIVE EXPERIENCE

- Experience developing and maintaining Infrastructure as Code using Terraform (or equivalent), alongside a strong understanding of CI/CD pipelines and modern sof