Principal Mobile Apps Platform Engineer

Salary: £46,000 - 86,000 per year

Requirements:

• Were looking for proven experience with Kotlin Multiplatform (KMP), Gradle, and Spring Boot.
• Were looking for experience building and supporting mobile applications, with proficiency in the development toolset for at least one platform: Swift, Xcode, and Instruments for iOS, or Kotlin, Jetpack, and Android Studio for Android.
• Were looking for a strong understanding of unit testing and RESTful API design, along with a commitment to refactoring and regression test automation.
• Were looking for experience mentoring and coaching engineers, sharing technical expertise, and advocating best practices across a team.

Responsibilities:

• Provide technical leadership for our server-driven UI platform, driving architectural scalability, performance, and long-term maintainability across our mobile applications.
• Maintain and evolve our server-driven UI framework, with most development time spent on our backend Kotlin services.
• Play a visible, strategic role in our system design and architecture decisions.
• Mentor team members and help our teams deliver high-quality solutions at scale.

Technologies:

• API
• Android
• Backend
• Gradle
• Support
• Kotlin
• Mobile
• REST
• Spring
• Spring Boot
• Swift
• Xcode
• iOS
• UX UI Design

More:

Were Autotrader, the UKs leading automotive marketplace, bringing vehicle buyers and sellers together and offering everything from cars to e-bikes and caravans. Were hiring a Principal Software Engineer to evolve the in-app experience for our car-buying app, which has been downloaded over 23 million times and serves more than 3 million monthly users. Our mobile apps team is helping us transition to a platform where consumers can buy vehicles entirely online. We use a Server-driven UI architecture and a custom client-side framework that renders data, context, and layout configurations from a federated backend REST API. Were a collaborative tech community that values pair programming, code reviews, stand-ups, and knowledge sharing. We offer a salary of £60,000–£80,000, an annual share award worth 10% of salary that vests in yearly instalments over three years, 28 days holiday plus bank holidays, private medical cover, a pension scheme with standard employer contributions of 7% and employee contributions of 5%, enhanced family leave, a car salary sacrifice scheme, share-save options, wellbeing support, and access to a 24/7 online GP and dentist. Our Connected Working hybrid model requires at least three days a week in the office, alongside remote-first periods at set times during summer and winter, when you can work remotely anywhere in the UK and from certain locations abroad.

last updated 40 week of 2026