Principal Android Engineer (Contract, Outside Ir35)

Hedgehog Lab; Ledston; Remote; GBP 111,000 - 185,000; Full time

Benefits offered by this job

Remote first

6-month contract

Job summary

Hedgehog Lab, a digital product consultancy, seeks a Principal Android Engineer to lead the technical side of a team delivering a UK bank's Android app. The role moves the app to Jetpack Compose, while maintaining Kotlin/Compose development in a remote-first environment.

You'll mentor engineers, set standards, and collaborate with client engineers to shape the approach and priorities of the migration. This 6-month contract offers impactful banking work and exposure to regulated apps.

Qualifications

• Senior or lead Android experience with Kotlin and Coroutines/Flow.
• Experience directing the technical direction of an Android app.
• Mentoring engineers and setting coding standards.
• Experience with Jetpack Compose and migrating from XML/Data Binding.
• Proficiency in MVVM and DI with Hilt/Dagger.
• Strong unit testing discipline and secure data handling.

Responsibilities

• Lead technical decisions, including architecture and Compose migration.
• Set coding, testing and code review standards for the team.
• Mentor senior engineers and align with client engineers on priorities.
• Collaborate with client engineers on approach and priorities.
• Build features in Kotlin/Compose within MVVM using Hilt/Dagger.
• Ensure data security and secure network calls; investigate defects.

Skills

Kotlin

Jetpack Compose

MVVM

Dependency Injection

Unit testing

Mobile security

Tools

Hilt

Dagger

JUnit/MockK

Job description

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