Senior Android Engineer in London

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 our Mobile team
Our Mobile team builds the travel companion in our customers’ pockets. They own the mobile app experience that helps millions of people travel smarter, from finding the right journey through to booking with confidence and managing their trip with ease.

As a Senior Android Engineer, you’ll join a cross-functional product team and play a key role in shaping high-quality Android experiences for our customers. You’ll work closely with Product, Backend, Web and iOS colleagues to deliver customer-focused improvements, while contributing technical leadership across Kotlin, Coroutines, Jetpack Compose, Dagger, SOLID principles, clean code and modern engineering practices.

In this role as a Senior Engineer at Trainline, you will:

• Design, build and improve high-quality Android features that help customers plan, book and manage their travel with confidence.
• Work as part of a cross-functional product team, contributing to technical decisions from discovery and design through to delivery and iteration.
• Identify and execute improvements that enhance app performance, reliability, developer experience and delivery speed.
• Partner closely with Product, Backend, Web and iOS colleagues to shape roadmaps, solve customer problems and deliver joined-up experiences across platforms.
• Use modern Android technologies and engineering practices, including Kotlin, Coroutines, Jetpack Compose, Dagger, continuous integration and clean architecture principles.
• Champion quality, maintainability and thoughtful technical design, helping the team make pragmatic decisions that support long-term product growth.
• Contribute to an agile engineering culture through collaboration, pair programming, continuous delivery and shared ownership of outcomes.
• Provide technical leadership within the Android space, helping to move initiatives forward and supporting strong engineering standards across the team.
• Mentor and support other engineers, sharing knowledge and creating an environment where people can learn, contribute and grow.

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

• Strong Android development experience, with good working knowledge of Kotlin and modern Android technologies.
• A solid understanding of design patterns, SOLID principles, clean code practices and continuous integration or continuous delivery.
• Experience building customer-facing mobile products where user experience, quality and performance are central to decision making.
• Confidence working with Git and collaborating with others through modern software development workflows.
• A collaborative approach to working in cross-functional teams, with the ability to communicate clearly with Product, Backend, Web, iOS and other engineering colleagues.
• A proactive mindset, with the ability to take initiative, bring people together and help move work forward in a thoughtful and inclusive way.
• An interest in mentoring others, sharing technical knowledge and supporting the growth of engineers around you.
• Helpful experience working across platforms or with backend technologies, although this is not essential.

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 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!