Principal Android Engineer (Contract, Outside Ir35)

Hedgehog Lab; Manchester; Hybrid; GBP 120,000 - 175,000; Full time

Job summary

Hedgehog Lab is seeking a Principal Android lead to steer the technical direction of an Android banking app migrating to Jetpack Compose. This remote-first contract runs for ~6 months, with an on-site expectation in the UK.

You'll shape the approach, set standards, mentor senior engineers and collaborate with client teams to deliver secure, high-quality Kotlin/Compose features in an MVVM setup using Hilt and Dagger.

Qualifications

• Senior Android experience with Kotlin and Coroutines/Flow.
• Lead the technical direction of an Android app and make architecture decisions.
• Mentor engineers and set coding standards for a team.
• Experience with Jetpack Compose and legacy XML/Data Binding.
• MVVM architecture with Hilt and Dagger.
• Unit testing and safe large-codebase changes.

Responsibilities

• Lead technical decisions, including architecture and migration to Compose.
• Set standards for coding, testing and code reviews.
• Mentor senior engineers on the team.
• Collaborate with client's engineers on approach and priorities.
• Build features in Kotlin/Compose within MVVM using Hilt/Dagger.
• Ensure data and network calls are secure.
• Lead investigations into defects and performance issues.

Skills

Android Kotlin

Jetpack Compose

MVVM with Hilt/Dagger

Android architecture

Mentoring engineers

Unit testing

Security of mobile apps

Tools

XML layouts

Data Binding

JUnit

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