Senior Mobile Engineer

Fuse Energy

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London, England, UK remote Until 9/6/2026 5+ years exp First posted March 25, 2026 Last posted July 8, 2026
Job description

Fuse Energy is a forward-thinking renewable energy startup on a mission to deliver a terawatt of renewable energy - fast. We're combining first-principles thinking with cutting-edge technology to build a radically better energy system. We raised $210M from top-tier investors including Multicoin, Balderton, Lakestar, Accel, Creandum, Lowercarbon, Ribbit, Box Group and strategic angels like Nico Rosberg, the Co-Founder of Solana and GPs behind Meta, Revolut, Spotify, Uber and more.

We're creating a fully integrated energy company: from developing solar, wind and hydrogen projects to real-time power trading and distributed energy installations. By selling directly to consumers, we cut out the middleman, lower costs and pass on savings to customers.

We're hiring Mobile Engineers to join a small, high-ownership team in our London office. This isn't a role where you'll be handed fully-specced tickets, you'll own features end-to-end, from customer-facing product to internal tools, including shipping consumer-facing AI features into production on mobile. You'll work in Swift and Kotlin across iOS and Android alongside a tight team of mobile and web engineers, on everything from expansion into new markets to the polish that makes an app feel effortless. Our infrastructure and backend are already excellent; we're looking for mobile engineers who bring the same bar of craft and ownership to match.

Responsibilities

    • Design, build, and maintain responsive, reusable, and reliable mobile applications for iOS and Android platforms
    • Own features end-to-end, from shaping the product idea through to shipping and iterating in production
    • Work closely with designers to implement high-quality UI/UX and ensure design consistency, with a real focus on craft and polish
    • Ship consumer-facing AI features into production on mobile, from on-device ML to in-app AI assistants
    • Contribute to architectural decisions to ensure scalability, maintainability, and flexibility of the mobile codebase
    • Test, debug, and resolve issues to maintain app stability and reliability
    • Troubleshoot production issues and provide timely resolutions to ensure smooth user experiences

Requirements

    • 5+ years of professional experience building mobile applications for iOS and Android
    • Proficiency in Swift or Kotlin, with deep expertise in at least one platform and the range to work across both
    • Strong grasp of mobile UI/UX principles and best practices for creating intuitive, responsive experiences, with a real eye for craft and detail
    • A track record of owning features end-to-end and contributing product ideas, not just executing specs
    • Hands-on experience integrating RESTful APIs with mobile applications
    • Familiarity with push notifications, messaging services, and related mobile frameworks
    • Understanding of mobile security fundamentals and ability to implement secure data handling

Benefits

    • Competitive salary and an equity sign-on bonus
    • Biannual bonus scheme
    • Fully expensed tech to match your needs
    • Paid annual leave
    • Breakfast and dinner allowance for office based employees
About this role

Summary

Develop and own mobile applications for iOS and Android, including AI features

Job title

Senior Mobile Engineer

Experience level

5+ years

Minimum experience

5+ years exp

Industry

renewable energy

Location requirements

London, UK; onsite role, no remote work

Salary

Not specified

Management role

No

Skills & keywords

Required skills

SwiftKotlinRESTful APIsUI/UXmobile security

Preferred skills

None specified

Specializations

iOSAndroidSwiftKotlinAI
Locations

Structured locations inferred from the posting.

London, UK

On-site City