Senior Backend Engineer - .Net

Trainline

About us 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.  Great journeys start with Trainline 🚄  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.  Today, we're a FTSE 250 company driven by our incredible team of over 1,000 Trainliners from 50+ nationalities, based across London, Paris, Barcelona, Milan, Edinburgh and Madrid. With our focus on growth in the UK and Europe, now is the perfect time to join us on this high-speed journey.  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!

Trainline

About us 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.  Great journeys start with Trainline 🚄  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.  Today, we're a FTSE 250 company driven by our incredible team of over 1,000 Trainliners from 50+ nationalities, based across London, Paris, Barcelona, Milan, Edinburgh and Madrid. With our focus on growth in the UK and Europe, now is the perfect time to join us on this high-speed journey.  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 software delivery practices. * Experience building and operating cloud-native applications using containers and orchestration technologies within AWS and Amazon ECS. AI EXPERIENCE * Experience using AI-assisted engineering tools to improve productivity, quality and software delivery, while applying sound judgement to validate outputs. * You're curious about the rapidly evolving AI landscape and can identify practical opportunities to apply AI to engineering workflows, automation and developer experience - ideally through first hand experience. COMMUNICATING AND INFLUENCE * A track record of influencing technical decisions across engineering teams through collaboration, clear communication and technical credibility. * Strong communication and collaboration skills, with the ability to explain technical concepts to diverse audiences, build trusted relationships and help drive organisational adoption of engineering standards and best practices. 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!

CarbonChain

ABOUT CARBONCHAIN Want to work on the most pressing challenge of our generation? If you have experience building exceptional products, know how to execute at scale, and want to help build a company for the long term, we'd love to hear from you. CarbonChain helps the world’s biggest supply chains measure and reduce their carbon emissions, using verified primary data where possible, and robust defaults where it isn’t. We build software that turns messy, real-world operational and supplier information into decision-grade carbon and compliance insights, so teams can act: improve sourcing, meet regulations like CBAM, and deliver credible reporting to customers, investors, and regulators. We’re a product-led company operating in a high-stakes domain. Data quality, auditability, reliability, and trust matter as much as speed. If you enjoy building systems that customers rely on, and shipping improvements that measurably change behaviour across a network, you’ll feel at home here. OUR PRODUCT Our platform combines real-world emissions data with our customers' supply chain information to create actionable insights. We help sustainability teams answer critical questions: Where are the emissions hotspots in our supply chain? Which suppliers should we prioritize? What's the carbon impact of switching vendors or routes? A major focus of what we’re building right now is supplier engagement and CBAM data management: * enabling installations (goods producers) to prepare, manage, and share CBAM datasets through guided product carbon accounting workflows; * improving our supplier database and connection management to support sharing across supply chains; * and building ingestion pipelines that turn messy customer files into structured, provenance-tracked, insights-ready data. Beyond CBAM, our platform supports product and corporate carbon footprinting used by some of the world’s largest commodities producers and traders, helping teams move from data collection to credible reporting and decision-making ABOUT THE ROLE We're looking for a Senior Backend Engineer to build robust, scalable systems that power our product. This is a high-impact individual contributor role where you'll own meaningful projects and directly influence how our engineering team works. You'll focus on shipping well-crafted backend systems while collaborating closely with the team to deliver features that solve real customer problems. We value engineers who take initiative, care about the details, and aren't afraid to venture beyond their primary domain when needed. WHAT YOU'LL DO * Design and build backend systems that handle complex carbon data workflows and integrations * Own features from technical design through deployment - you'll drive your projects forward with autonomy * Write clean, maintainable code and establish patterns that other engineers can follow * Collaborate with Product Managers and designers to translate product requirements into technical solutions * Contribute to architectural decisions and help shape our technical standards * Occasionally jump into frontend work when needed - we value versatility and believe the best solutions come from understanding the full picture * Participate in code reviews and help maintain high engineering standards across the team WHAT WE'RE LOOKING FOR * 5+ years building complex software systems across the full development lifecycle * Strong backend engineering skills with experience building modern web applications * Deep knowledge of Python and familiarity with frontend technologies like TypeScript * Hands-on experience with relational databases, job queues, and asynchronous processing * Knowledge of IaC/Terraform and modern CI/CD practices * Strong collaboration skills—you work closely with Product to ideate features, advise on trade-offs, and iterate on what we've built * A product-minded approach: you understand why you're building something, not just how * Bonus: startup or SaaS experience * Bonus: experience with data-intensive systems or climate/sustainability tech   WHAT WE OFFER Meaningful impact and accelerated growth This is a rare opportunity to work on technology that directly addresses the climate crisis while shaping the future of a fast-growing company. You'll have significant influence over our technical direction and product strategy - the kind of impact that typically takes decades to achieve elsewhere. You'll tackle diverse challenges, work across the full stack of problems (technical and otherwise), and own meaningful projects from start to finish. If you want to learn quickly, take on real responsibility, and see the direct results of your work, this is the place to do it. Competitive salary and benefits: * 28 days annual leave * £500 home office setup allowance * £2,000 annual learning allowance * Private healthcare * Generous parental leave policy * Weekly team lunches in the office * Office gym, and cycle to work scheme CarbonChain values diversity and inclusion and welcomes applications from candidates with diverse backgrounds.  If you think your skills and experience match what we’re looking for and you’d like to join the next Climate Tech industry unicorn, please get in touch! You can find out more about interviewing at CarbonChain at https://www.carbonchain.com/careers/interview-process.