Senior Backend Engineer - .Net

Trainline; Greater London; Hybrid; GBP 85,000 - 95,000; Full time

Benefits offered by this job

Private healthcare

Dental insurance

Hybrid work model

Work from abroad policy

Job summary

Trainline in London is seeking a senior .NET Engineer to own features end-to-end in a high-traffic platform serving millions of travellers.

You will mentor engineers, design scalable microservices, and work across identity, cloud, CI/CD, and observability. The role involves hands-on coding in C#/.NET 6-10 and collaborating with front-end teams to deliver end-to-end customer experiences.

Qualifications

• Experience mentoring engineers and comfortable pair-programming.
• Hands on experience with C# .NET and latest features.
• Experience collaborating with front-end engineers to deliver end‑to‑end features.
• Experience with identity and authentication systems (IdentityServer, OpenID Connect, OAuth2).
• Experience designing and maintaining CI/CD pipelines (GitHub Actions, TeamCity, Spacelift).
• Experience with cloud platforms (AWS preferred; Azure or GCP also valuable).
• Hands-on experience with Infrastructure as Code, particularly Terraform.
• Strong observability experience (logging, monitoring, alerting).
• Familiarity with New Relic and ELK stack (or equivalents).
• Curiosity about AI and emerging tools.
• Experience supporting production systems and reliability.
• Experience building and operating microservices architectures.
• Experience with event-driven systems and asynchronous messaging.
• Solid understanding of distributed systems and scalability challenges.
• Excellent communication skills.

Responsibilities

• Deliver new functionality or features using the most appropriate tools & techniques.
• Ensure quality is at the heart of everything you and your team do.
• Continuously improve the code base.
• Keep our customer as the number one priority.
• Identify blockers, boulders, time sinks and waste and remove them.
• Make significant contribution to technical decisions.
• Act as a coach and mentor to others in the team.
• Take full ownership of the development lifecycle from code to production, including deployment and monitoring.

Skills

Mentoring

C# .NET

Frontend collaboration

Identity systems

CI/CD pipelines

Cloud platforms

Terraform

Observability

Distributed systems

Microservices

Event-driven

Communication skills

Tools

New Relic

ELK stack

AWS

Docker

Terraform

Job description

About us

At Trainline, our purpose is to empower greener travel choices, connecting people and places. 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 Backend teams at Trainline

The Backend teams at Trainline build the core of Trainline’s world class product. We create the journey search functionality that millions of our customers use on a daily basis, the eCommerce platform that provides a secure and seamless experience and we connect Trainline to over 270 travel operating companies, across 45 countries in Europe and the rest of the world. Each team has a targeted domain focus, ranging between journey search, fares calculation, bookings, fulfilment, payments, refunds, carriers’ integrations, real-time timetable information, journey disruptions and much more.

As a senior level .NET Engineer at Trainline you will

• Deliver new functionality or features, using the most appropriate tools & techniques
• Ensure quality is at the heart of everything you and your team do
• Continuously improve the code base
• Keep our customer as the number one priority
• Actively identify blockers, boulders, time sinks and waste, and actively attempt to remove them
• Make significant contribution to technical decisions
• Act as a coach and mentor to others in the team
• Take full ownership of the development lifecycle from code to production, including deployment and monitoring

Our Tech Stack

• Languages & Frameworks: C# (.NET 6–10)
• Databases: DynamoDB, PostgreSQL
• Cloud & Infrastructure: AWS Cloud, Docker, Terraform
• CI/CD & DevOps: GitHub Actions
• Monitoring & Logging: New Relic, ELK Stack

We’d love to hear from you if you have

• Experience mentoring less experienced engineers and comfortable pair-programming with colleagues
• Hands on experience with C# .NET and the latest features
• Experience collaborating with front-end engineers and other disciplines to deliver end-to-end features and cross-functional epics
• Experience working with identity and authentication systems (e.g. IdentityServer, OpenID Connect, OAuth2)
• Experience designing and maintaining CI/CD pipelines (e.g. GitHub Actions, TeamCity, Spacelift or similar tools)
• Experience with cloud platforms (AWS preferred; Azure or GCP also valuable)
• Hands-on experience with Infrastructure as Code, particularly Terraform
• Strong experience with observability practices (logging, monitoring, alerting)
• Familiarity with tools such as New Relic and ELK stack (or equivalents)
• Curiosity about AI and emerging tools
• Experience supporting production systems and improving reliability
• Strong experience building and operating microservices architectures
• Experience with event-driven systems and asynchronous messaging patterns
• Solid understanding of distributed systems and scalability challenges
• Have excellent communication skills

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 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 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!

Compensation: £85K – £95K

• £85K – £95K