Senior iOS Engineer

Sumup

ABOUT THE ROLE At SumUp, we're on a mission to bring merchants and consumers closer together and help local communities thrive. With SumUp Consumer, we're building a rewarding banking experience that connects people to the small businesses they love while enabling free transactions for our merchants. SumUp Consumer helps consumers manage their money with ease and get more from everyday spending. It offers seamless payment experiences and financial tools designed for modern life—spanning banking, cards, savings, and open banking. This is a high-impact, hands-on engineering role where you'll own the development and quality of the SumUp Consumer iOS application. You'll work directly on the features that consumers interact with every day, collaborating closely with Backend Engineers, Product Managers, Designers, and Android Engineers to deliver polished, reliable, and impactful mobile experiences. WHAT YOU’LL DO * Build and ship features across key consumer banking product areas—including KYC flows, card management, savings, open banking consent, and payment experiences. * Write clean, testable Swift code and participate actively in code reviews to uphold high engineering standards across the codebase. * Contribute to and evolve the iOS app architecture, including modularisation, dependency management, and scalability patterns as the product grows. * Own performance and reliability by monitoring crash rates, proactively identifying issues, and driving app stability before they impact consumers. * Maintain a culture of quality by writing unit and UI tests and contributing to the health of our CI/CD pipelines. * Collaborate cross-functionally with Backend Engineers on API design, Product Managers on roadmap priorities, and Designers on seamless user experiences. WHAT MAKES YOU GREAT FOR THIS POSITION * Strong proficiency in Swift and deep knowledge of the iOS framework (Objective-C knowledge is a plus). * Solid understanding of RESTful API integration and experience working with backend engineers on API design. * Experience working with agile methodologies, CI/CD pipelines, and pair programming. * Deep care for user interaction, usability, and interface quality—you build things that feel great to use. * Ability to understand a large problem, design a solution, break it into deliverable chunks, and ship it independently. * Passion for clean, maintainable, and testable code and a genuine pride in your craft. * Mature, business-minded approach—balancing high-quality engineering with pragmatism in a fast-paced environment. * Self-driven and proactive nature, comfortable owning a domain with limited direct oversight. * Previous experience in payments, financial services, or fintech environments is a strong plus. WHY YOU SHOULD JOIN SUMUP 🌎 Opportunity to work with SumUppers globally on large-scale fintech products used by millions of businesses worldwide. 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced. 🚀 Enrolment onto our Virtual Stock Option programme: you will own a stake in SumUp’s future success. 📚 A dedicated annual L&D budget for your individual development, which can be used to attend conferences and/or advancing your career through further education. 💶 Competitive Health & Life Insurance: Includes comprehensive cover (optical, dental) and Life Assurance (2 x your salary). 💰 Financial Future: A corporate pension scheme and a referral bonus for bringing in top talent. 🏖️ Generous time off: 28 days of paid leave plus public holidays and special leave days. 🌴 Break4me: 1-month paid sabbatical after 3 years of service. 🎉 Culture of Connection: Attend global offsites and/or hackathons with your teammates.   ABOUT SUMUP Be empowered to do more that matters. At SumUp, we're on a mission to empower small businesses across the globe by providing a vast set of simple and affordable business tools to help them start, run, and grow their businesses. Today, over 4 million businesses in 36 markets rely on SumUp as their financial partner to manage payments, finance and customer relationships. Our commitment to small businesses is reflected in our diverse team of over 3,000 SumUppers from over 90 nationalities, united by global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster an inclusivity and continuous learning culture, providing a safe space for personal and professional growth. Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify. SumUp is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.

Proton

About Proton  Join Proton and build a better internet where privacy is the default Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives! We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 500+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here! The Role Based in our London office, you’ll join one of several high-impact product teams across Proton Mail, Proton Drive, and Proton Wallet/Payments and Proton Account, helping build privacy-first products used by millions around the world. Whether it’s secure communication, encrypted cloud storage, or the future of private financial tools, you’ll work on technically ambitious products with real-world impact. As a senior engineer, you’ll collaborate closely with product, design, and engineers across Proton to build and ship high-quality experiences on Apple platforms, helping define what “great” looks like for privacy-focused consumer products at scale. What we are looking for * You have extensive experience building and shipping high-quality iOS applications * You care deeply about product quality, usability, and delivering exceptional user experiences * You have strong experience building maintainable, scalable, and testable mobile architectures * You are comfortable working across large codebases and collaborating across multiple teams * You have experience mentoring engineers and raising the technical bar within a team * You have a strong understanding of performance, concurrency, and mobile memory management * You are comfortable navigating ambiguity and contributing to product and technical discussions * Experience with privacy, security, encryption, sync systems, or offline-first architectures is a strong plus * Rust experience is a plus, but not required as we continue moving towards a platform-independent Rust logical core communicating with the iOS application via generic interfaces What We Offer * Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here) * Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win. * Technology: you'll get the right hardware and the right software you need to do your best work. * Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one. * Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day * In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building * Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch. * Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you. * Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Flo Health

500M+ downloads. 80M+ monthly users. A decade of building – and we’re still accelerating. Flo is the world’s #1 health & fitness app worldwide on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down. With 7M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better. The job As an iOS Engineer at Flo, you'll help shape the mobile experience for millions of people, and do genuinely meaningful work in women's health. Our app is trusted by 1 in 4 women aged 18–44 in the US and used across 100+ countries, with machine learning and AI powering accurate cycle predictions and personalised, medically credible health insights. We build large-scale mobile applications with rich, intuitive interfaces - optimised for speed, accessibility and privacy. You'll join a cross-functional team working across the full mobile lifecycle, from feature ideation through to release and iteration, with real ownership over value delivery end to end. We're not a feature factory. Our engineers are pragmatic problem-solvers who thrive in fast-moving environments and care about what they ship. You'll have genuine scope to experiment, lead ambitious product initiatives and implement solutions that matter - not just clear a backlog. Flo is a constantly evolving product, and we give our engineers the trust and autonomy to evolve it. Your Experience Must have: * 6+ years in software engineering, with at least 3 years focused on building, shipping, and maintaining production mobile applications. * Expert-level iOS development skills, with a proven track record of delivering high-quality apps at scale. * Hands-on experience building complex mobile applications with rich, performant UIs — experience in global consumer-facing products is a strong plus. * Deep proficiency in Swift; working knowledge of Objective-C and solid object-oriented design principles. * Strong familiarity with Apple's ecosystem — frameworks, HIG guidelines, and end-to-end App Store submission and maintenance processes. * Clear understanding of the mobile product lifecycle and comfortable working within Agile teams. * A collaborative, growth-oriented mindset with the drive to take ownership and deliver. Nice to have: * Solid understanding of UX and interaction design principles, with the ability to collaborate effectively with designers and advocate for quality user experiences. * Proven experience optimizing mobile app performance over constrained networks, including building and maintaining offline-first architectures. * Hands-on experience with mobile CI/CD pipelines, including build automation, automated testing, and release workflows. * Experience integrating with BI and analytics platforms, with familiarity in designing and interpreting A/B tests to drive product decisions. What you'll be doing You'll be responsible for: * Building and maintaining features using modern frameworks, libraries, and internal component systems, ensuring consistency, scalability, and code quality across the codebase. * Delivering polished, engaging user experiences that balance visual appeal with intuitive interaction design. * Owning and contributing to a robust Continuous Delivery pipeline, ensuring fast, reliable, and safe releases to production. #LI-Hybrid #LI-AJ1 Annual Salary Range (ranges may vary based on skills and experience) £95,000—£120,000 GBP How we work We’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar. You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it.  What you'll get We support impact with meaningful reward. Here’s what that looks like: * Competitive salary and annual reviews * Opportunity to participate in Flo’s performance incentive scheme * Paid holiday, sick leave, and female health leave * Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents * Accelerated professional growth through world-changing work and learning support * In-person collaboration and work in a hybrid model, with 3 days per week spent in the office * 5-week fully paid sabbatical at 5-year Floversary * Flo Premium for friends & family, plus more health, pension and wellbeing perks Diversity, equity and inclusion Our strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants.