Senior Mobile Engineer

Crosscut; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Generous stock options

25 days annual leave PLUS Bank HOLIDAY

Private medical and dental insurance

9% employer pension contributions

Learning and development budget

Personal equipment budget

Enhanced family leave policies

Life assurance of 4x salary

Job summary

Omaze in London seeks a Senior Mobile Engineer to own the mobile experience across iOS and Android. You’ll work primarily with React Native and Expo, with native Swift/Kotlin when needed to optimise performance.

You’ll collaborate with product and UX from early stages, contribute to release pipelines, and help set mobile standards while leveraging AI-assisted tooling to maintain a premium user experience.

Qualifications

• Significant experience as a mobile engineer with RN and Expo.
• Strong focus on performance, frame rates, and smooth UX.
• Experience with EAS build and submission workflows.
• Ability to work across iOS and Android in a shared React Native codebase.

Responsibilities

• Own the design, implementation, and testing of features across TypeScript, React Native and Expo.
• Collaborate with product and UX from early stages to shape design decisions.
• Ensure end-to-end quality: well-tested components and robust production behaviour.
• Contribute to release pipelines and build/deploy workflows for frequent shipping.
• Uphold mobile engineering standards, performance budgets, and conventions.
• Apply AI-assisted coding tools with rigorous judgement for generated code.

Skills

React Native

Expo

Performance optimization

iOS/Android

Swift/Kotlin

Automated testing

App Store submission

Code quality

Tools

EAS Build

Jest

Maestro

Appium

Job description

Senior Mobile Engineer

Location: Holborn, London

Office Policy: 3 days in person, 2 days at home each week

Who We Are

At Omaze, we give our community in the UK and Germany the chance to win luxury homes and other life‑changing prizes — all while raising money for the causes they love.

Thanks to our Omaze Community, we’ve raised over £100 million for UK charities in just five years. That’s millions helping organisations like Age UK, the RSPCA, British Heart Foundation and Great Ormond Street Hospital Charity deliver life‑saving work.

And the best part? We’re only just getting started. Omaze is building a business and culture committed to growth and creating significant social impact on a global scale.

Why You’ll Love Working at Omaze

• Growth: Omaze is one of the fastest‑growing companies in the world.

• Impact: Join a team of world changers dedicated to creating a ripple effect of good.

• Pioneering: Be part of something no one has done before.

• Culture: We work hard, grow together, and spread joy along the way.

What you'll be doing

As a Senior Mobile Engineer at Omaze, you take genuine ownership of the mobile experience our customers rely on and you care deeply about getting it right. React Native and Expo are your primary tools, and you're experienced enough with both to know their strengths, their limits, and when to reach beyond them. That's where your native knowledge comes in: whether it's Swift, Kotlin, or both, you're comfortable dropping into native code when the situation calls for it when it comes to performance, platform APIs, or something Expo just can't do out of the box. At Omaze, we are aiming for our app to not just be a utility but a premium experience.

What You’ll Be Doing

• Own the design, implementation, and testing of features across our TypeScript, React Native and Expo codebase, producing code that's performant, maintainable, and delivers a genuinely great user experience on both iOS and Android.

• Work closely with product and UX from the earliest stages of a feature, contributing to interaction and technical design decisions before they're hard to change.

• Own the quality of what you ship end-to-end: writing well‑tested components, holding a high bar in code review, and taking responsibility for production behaviour.

• Contribute to release pipeline and EAS build and deployment workflows to help the team ship frequently, safely, and with confidence.

• Uphold and actively contribute to mobile engineering standards and best practices, patterns, performance budgets, and platform‑specific conventions that keep the codebase healthy as it grows.

• Use AI‑assisted and agentic coding tools as a natural part of your workflow, applying the same rigour and judgement to AI‑generated code as you would to anything hand‑written.

About You

• Passionate about mobile craft: you notice when an animation is 2ms off, when a transition doesn't feel quite right, or when a scroll list isn't as smooth as it should be and you do something about it.

• You understand that for a premium experience, performance is the product. You think about frame rates, responsiveness, and perceived speed not as nice‑to‑haves but as core quality requirements, and you have the tools and instincts to measure, diagnose, and raise the bar.

• Significant experience as a mobile engineer, with strong hands‑on expertise in React Native and Expo, including EAS build and submission workflows.

• Comfortable working across iOS and Android within a shared React Native codebase, with a solid understanding of platform‑specific behaviour and constraints.

• Native mobile experience in Swift (iOS) and/or Kotlin (Android) is desirable. You can read, write, and debug native code.

• Strong understanding of mobile performance. You know how to diagnose and fix issues across JS thread, native thread, and render pipeline.

• Experience with automated testing for mobile unit, integration, and end‑to‑end (e.g. Jest, Maestro, Appium).

• Familiar with App Store and Google Play submission, review processes, and release management.

• A collaborative, clear communicator who works well with product, UX, and backend engineers. You can translate mobile constraints into language the whole team understands.

What’s In It For You

• Generous stock options scheme

• 25 days annual leave PLUS Bank Holidays

• Private medical and dental insurance

• 9% employer pension contributions, when you contribute at least 2%

• A generous personal learning and development budget each year to use on training courses, conferences and professional memberships

• Personal equipment budget to work from home

• Enhanced family leave policies

• Life assurance of 4x your salary

DEI Statement

We actively seek out diversity of thought and experience to drive innovation. We welcome all backgrounds, identities, and perspectives and work hard to ensure that every Omaze employee can bring their authentic self to work at all times.