Senior iOS Engineer

About the role

This page outlines the opportunity to join the SumUp Consumer team as a Senior iOS Engineer. The role centers on owning the end-to-end lifecycle of the iOS application, with a focus on building features that strengthen the connection between local merchants and consumers. You will operate with a high degree of autonomy, delivering high-impact work that directly shapes the daily experience of users.

The position is based in London, England, United Kingdom, and is a full-time engagement. The compensation package for this role ranges from £65,000 to £90,000 per year.

What You'll Do

You will be responsible for designing and implementing intuitive user flows, with a primary focus on areas such as card management and savings functionality. This involves architecting modular iOS structures and managing dependencies to ensure the application can scale effectively as product requirements evolve.

A key part of the role involves monitoring application health by analyzing crash data and performance metrics. You will proactively identify potential issues and drive improvements to ensure a stable and reliable experience for consumers before problems affect them.

You will write clean, testable Swift code and actively participate in code reviews. This includes implementing solutions and evaluating the work of peers to maintain high engineering standards across the entire codebase. Collaboration is central to the position; you will work closely with Backend Engineers to define API contracts and coordinate with Android Engineers to ensure feature parity and consistent behavior across platforms.

The role requires partnership with the Design team to refine user interactions, ensuring that the interface feels smooth, coherent, and delightful to use. You will own complex feature areas such as KYC workflows and open banking consent processes, guiding these features from initial concept through to production release. You will also contribute to the evolution of the iOS architecture, including modularization, dependency management, and the adoption of scalability patterns.

Advancing the CI pipeline is another core responsibility. You will work to ensure that quality checks, tests, and other safety nets are integrated into the delivery process, enabling the team to move with speed while maintaining reliability.

What Makes You a Strong Fit

Success in this role requires strong proficiency in Swift and a deep understanding of iOS development principles. You must be comfortable writing code for the iOS environment and know when to apply Objective-C where necessary. A solid grasp of RESTful API integration is essential, as you will work alongside backend teams to design and consume services.

You should have experience working within agile development cycles and CI/CD environments. The ability to break down large, complex problems into manageable, deliverable tasks is critical. You must be able to independently own a domain from design through implementation.

A strong focus on usability and interface quality is required. You should care deeply about the end-user experience and build products that are functional and elegant. The role demands a mature, business-minded approach, balancing high-quality engineering standards with pragmatic decision-making in a fast-paced setting.

Self-direction is a core requirement. You must be comfortable taking ownership of responsibilities with minimal direct oversight. While prior experience in payments, financial services, or fintech is listed as a strong advantage, it is evaluated alongside your overall technical capability and mindset.

Previous contributions to open source projects or public portfolios that demonstrate craftsmanship and engineering rigor are considered a positive signal. Proficiency with the tools used in the SumUp Consumer ecosystem, including Swift, iOS, Agile methodologies, CI/CD systems, and Git, is expected.

Why Join SumUp

This role offers the chance to work on large-scale fintech products used by millions of businesses globally. You will collaborate with SumUppers from diverse backgrounds on projects that matter to local communities.

SumUp is committed to fostering a diverse and inclusive workplace where a wide range of perspectives is respected and valued. The company offers opportunities for professional growth, including a dedicated learning and development budget that can be used for conferences or further education.

Additional benefits include a corporate pension scheme, comprehensive health and life insurance, generous paid leave, and access to the Virtual Stock Option programme, which allows employees to share in the company's future success.