Senior Software Engineer (Mobile, React Native)

Nine Elms, London - Full-time (3 days a week on-site)

Zapp is building the future of convenience with a full stack approach to on-demand essential items, 24/7, delivered in minutes. Customer obsession is at the heart of everything we do. From app users to frontline staff to store workers, we are relentlessly focused on delighting our customers. We are backed by the world's leading investors and our team has scale-up and exit experience at companies such as Amazon, Jumia, Deliveroo, Tesco, Stuart and Just Eat. If you're ready to help build the world's most customer-focused company, get in touch. We are an AI-first company. We don't just build software, we build intelligent systems. From AI-assisted development workflows to LLM-powered product features, we expect our engineers to embrace and actively contribute to how AI is reshaping the way we work and what we ship. As a Senior Software Engineer (Mobile, React Native) at Zapp, you will be a core contributor to our consumer-facing iOS, Android, and web experiences. You will work closely with product and design to ship high-quality features, raise the technical bar through great code and thoughtful review, and help the team move fast without breaking things.

Responsibilities

• Build and ship high-quality features across our React Native consumer app on iOS, Android, and web

• Write clean, well-tested, performant code and contribute to a high standard of engineering across the team

• Collaborate with product managers and designers to turn ideas into polished, reliable user experiences

• Profile and optimise app performance, stability, and responsiveness

• Participate actively in code reviews, helping maintain quality and share knowledge across the team

• Integrate AI-powered features into the app, including working with LLM APIs and on-device AI capabilities

• Leverage AI tooling (e.g. Claude, Cursor, Copilot) to accelerate your own delivery and contribute to team-wide best practices

• Contribute to architectural discussions and help establish mobile engineering patterns and standards

• Work across the stack where needed, including backend APIs and data layers that support the mobile experience Requirements

• At least 5 years of professional experience building B2C consumer mobile apps (essential)

• Deep expertise in React Native across iOS and Android (essential)

Requirements

• At least 5 years of professional experience building B2C consumer mobile apps (essential)

• Deep expertise in React Native across iOS and Android (essential)

• Strong TypeScript skills, with experience in Node.js frameworks (e.g. Express, Fastify) a plus

• Experience with React.js or React Native for Web for cross-platform delivery

• Solid understanding of mobile performance, app stability, and release processes

• Practical experience building with or integrating AI/LLM APIs and familiarity with AI-assisted development workflows

• Solid understanding of mobile security best practices, including secure storage, authentication patterns, and API security

• Comfortable working autonomously and taking end-to-end ownership of features

• Strong written and verbal communication skills

• Knowledge of GraphQL, Kotlin, Swift, or AWS is a plus

Benefits:

• Competitive salary & equity package.

• Enjoy 25 days of holiday per year (plus all bank holidays).

• Private Health Insurance.

• Extended sick pay and maternity/paternity leave pay.

• Cycle to work scheme.

• Flexible/hybrid working arrangement