Principal Android Engineer

**A lot of Principal roles take you away from the code.** Here you'll lead the technical side of a hedgehog lab team delivering a UK bank's Android app as it moves to Jetpack Compose, and still build alongside them. It's a contract outside IR35, expected to start in January 2027 and run for around 6 months. You'll work remote first, [on-site expectation]What's in it for you You'll shape how a large banking app moves to Compose, from the approach the team takes to the standards it follows. You'll lead a consultancy team that owns the delivery, with engineers who take testing and code reviews seriously. You'll add regulated banking work to your CV, which carries weight on future contracts. **Who you'll be doing it for** hedgehog lab is a digital product consultancy with 20 years of experience helping public and private sector organisations through digital transformation. We're B Corp and Great Place to Work certified. You'll lead a hedgehog lab delivery team working on our client's customer-facing Android app. Our client is a well-known UK bank. **What you'll be doing** - Leading the team's technical decisions, including architecture and the move from XML and Data Binding to Compose - Setting coding, testing and code review standards for the team - Mentoring the Senior engineers - Working with the client's own engineers on technical approach and priorities - Building features in Kotlin and Compose within an MVVM architecture using Hilt and Dagger - Making sure sensitive data and network calls are handled securely - Leading investigations into defects and performance issues **Experience you must have** - Commercial Android experience at a senior or lead level, in Kotlin with Coroutines and Flow - Leading the technical direction of an Android app, including architecture decisions - Mentoring engineers and setting standards for a team - Jetpack Compose, plus XML layouts, Data Binding and enough Java to work on older code - MVVM and dependency injection with Hilt and Dagger - Unit testing with JUnit and MockK, and using tests to make safe changes in large codebases - Mobile security, particularly protecting sensitive data and securing network calls **Experience that's nice to have** - Banking, fintech or other regulated apps - SAFe or another scaled agile framework - Leading a migration from XML screens to Compose - UI testing with Espresso or Compose - Certificate pinning, code obfuscation and root detection - CI/CD pipelines and mobile release processes - Accessibility experience **How to apply** If this sounds like you, apply below and we'll be in touch.