Senior iOS Engineer

Spectrum Search is partnered with a well-backed, early-stage fintech company seeking an experienced iOS engineer to build and launch its first mobile trading application.

About the opportunity

The company is developing trading technology that makes complex financial products easier to access through a cohesive user experience. Its founders bring experience in trading infrastructure and engineering low-latency systems.

This opportunity offers ownership of a new mobile product, from architectural decisions through to its first production release. The successful candidate will work alongside an established engineering team, with scope to help grow the mobile function. Equity participation and performance bonus potential are included.

The role

This is a full-time position for an engineer who has taken an iOS application from initial development through to release on the Apple App Store.

Working closely with the founders and frontend engineers, the successful candidate will translate a sophisticated web trading experience into a responsive native mobile application. The role combines hands-on Swift development, product judgement and responsibility for the foundations that future mobile engineers will build upon.

Key responsibilities

• Build the first native iOS trading application, supporting live market data, complex order types and connectivity across trading venues.
• Own mobile architecture, code quality and technical foundations, prioritising reliability, numerical accuracy and maintainability.
• Develop intuitive, gesture-driven interfaces and interactive charts that make complex trading information accessible on a small screen.
• Integrate REST APIs and WebSocket streams, managing connections, reconnection, synchronised price feeds and cached device state.
• Implement mobile wallet integrations, biometric authentication, transaction signing and secure on-device key storage.
• Lead the App Store release lifecycle, including provisioning, submission, review and production deployment.
• Establish continuous integration and continuous delivery pipelines for automated builds, previews, testing and rollbacks.
• Collaborate with frontend engineers on consistent design and functionality, and mentor mobile engineers as the team grows.

Essential requirements

• Strong native iOS development experience using Swift, with sound knowledge of the platform and engineering fundamentals.
• Meaningful ownership of an application built from the ground up and shipped through the Apple App Store release process.
• Experience handling real-time data streams and WebSockets, including connection resilience and UI responsiveness.
• Strong user interface and user experience judgement, including wireframing, prototyping and gesture-driven interactions.
• Ability to own a codebase, make architectural decisions and explain technical trade-offs.
• Ability to write, understand and debug production code independently, while using AI development tools thoughtfully.
• Demonstrable interest in trading through professional experience, personal projects or active engagement with financial markets.

Nice-to-haves

• Experience building mobile products in fintech, trading, digital assets or other real-time data environments.
• Experience within a venture-backed startup.
• A portfolio or public GitHub projects demonstrating relevant iOS work.

Location and remote setup

The role is based in New York City and requires attendance in the office five days per week.

Visa support may be available for eligible TN and O-1 candidates, and H-1B transfers where at least three years remain. New H-1B lottery sponsorship is not available.