Mobile App Developer (iOS / Flutter / React Native)

Mobile Engineer (iOS / Flutter / React Native) | FinTech | Newcastle (Onsite) | Up to £120k+

If you’re a strong mobile engineer who wants more than incremental app feature work, this is a chance to build a high-performance FinTech product at the core of a real trading and financial systems platform.

We’re working with a rapidly scaling startup building technology in partnership with an established hedge fund. They’re creating a new engineering hub in Newcastle, and mobile is a key interface into the platform.

This isn’t a typical “marketing app” or CRUD mobile build. You’ll be working on a real-time, data-heavy mobile product that surfaces trading, risk, and financial decisioning tools used in live environments.

The business is well-funded, already commercially validated, and early enough that the mobile stack, architecture, and UX patterns are still being actively defined. This is a genuine opportunity to shape the product from the ground up.

What you’ll be doing

You’ll take ownership of mobile experiences end-to-end across iOS and cross-platform development:

• Building and maintaining high-performance mobile applications in Swift (iOS), Flutter, or React Native
• Designing scalable mobile architecture for a real-time, data-intensive FinTech product
• Integrating complex backend systems (trading, risk, analytics, and pricing data)
• Working closely with backend engineers and quants to surface complex financial information in a clear, usable way
• Making key decisions around mobile architecture, performance, and UX
• Helping define mobile engineering standards and best practices in a scaling team

Tech environment

• iOS (Swift) for native development
• Flutter and/or React Native for cross-platform mobile development
• API-driven, real-time data systems
• Exposure to distributed backend / FinTech systems
• Strong engineering fundamentals over framework preference

Why Newcastle?

This is a full-time onsite role (Mon–Fri) in brand-new central Newcastle offices.

The environment is designed for focus and high-quality engineering:

• Modern offices with city and countryside views
• Strong social engineering culture (many recent relocations)
• Walk/cycle-friendly location with onsite facilities
• Stable working hours (09:00–18:00) with flexibility where needed
• Strong relocation support for UK-based candidates

What they’re looking for

We’re looking for strong mobile engineers who care about building polished, performant products across platforms.

• Strong experience in mobile development (iOS / Flutter / React Native)
• Proven track record shipping production mobile apps
• Strong understanding of mobile architecture patterns (state management, modular design, etc.)
• Experience working with complex APIs and real-time data
• Strong Computer Science fundamentals (OOP, data structures, algorithms, design patterns)
• Product-minded engineer who cares about performance and UX
• Comfortable working in a small, fast-moving engineering team shaping a platform from early stage

Package

• Salary up to £120,000+ (flexible for exceptional candidates)
• Bonus
• 25 days holiday
• Private healthcare (Bupa)
• Pension contribution
• Strong career progression in a scaling FinTech platform
• Social, tight-knit team culture with events and Friday early finishes
• Strong relocation support for UK-based candidates

Must have UK right to work (no sponsorship available).