iOS Developer in London

What We Do

At Heat Geek, we are tackling one of the UK’s biggest carbon contributors: home heating. 20% of all UK carbon emissions stems from home heating – and that contribution is even bigger on a global scale. At Heat Geek, we are changing that. By simplifying a traditionally complex industry and revolutionising the technology used by installers, we’re making low-carbon heating mainstream. We are on track to prevent 1,000,000 kg of carbon from entering our atmosphere in Q1 of 2026, and we won’t stop there!

Join Us!

People are at the core of who we are and what we do. From decreasing homeowners’ energy bills to help with the cost of living, to empowering talented heating engineers to perform outstanding installations, to ensuring a greener world for all of us, we believe in the power of what we can all do together. We need passionate, talented, hard-working people to be a part of this journey.

Your Mission

Our Heat Geek community is excited to bring an iOS Developer into our team. This is your opportunity to take on a role that’s vital to how we build and evolve Heat Geek’s mobile experience. As an iOS Developer, you’ll help design, build, and maintain high-quality iOS applications that support both our internal teams and our wider Heat Geek community. You’ll work closely with product, design, and backend engineers to solve complex, real-world problems — turning ambiguity into reliable solutions.

Role Outputs

• Build, ship, and maintain high-quality iOS applications using modern Apple technologies
• Take ownership of features from concept through to production and iteration
• Collaborate closely with product managers, designers, and backend engineers to deliver impactful user experiences
• Write clean, testable, and maintainable code that scales as our products grow
• Debug, improve performance, and continuously raise the quality bar of our iOS codebase
• Contribute to technical discussions, architectural decisions, and best practices within the engineering team

Candidate Requirements

• Professional experience developing iOS applications
• Strong knowledge of Swift and Apple’s iOS ecosystem
• Ability to take ownership of problems and work autonomously from idea to implementation
• Comfort working in complex, non-trivial problem domains
• A demonstrated passion for learning, improving, and building great software

It’s a bonus if you have…

• Experience with modern iOS technologies such as SwiftUI, Combine, TCA, or ARKit
• Exposure to full-stack development or an interest in how mobile apps interact with backend systems
• Experience with heat pumps, renewable energy, construction, or utilities

We believe great teams are built from different ways of thinking, learning, and living, and as such, we strive to build an organisation where people can show up as themselves. Even if you don’t tick every box listed above, but are passionate about the work that we are doing and believe that you can make a positive impact here, we’d love to hear from you. So please drop us a message or share more detail in your application!

Ways of Working + Benefits

This is a 3-day-in-the-office hybrid role where you will work with the team at our office in Sustainable Ventures in Waterloo, Europe's biggest climate tech hub. It's a 5-minute walk from Waterloo Station and an energising space for anyone working on climate change.

Some of our measurable benefits include:

• £5,000 contribution towards your own heat pump installation
• Shares in the company, allocated under a tax-incentivised scheme
• Salary that’s evaluated regularly, and based on skills, impact, and role scope—not negotiation tactics
• Private medical & dental insurance
• Learning and development budget
• Annual summer retreat
• Gym membership contribution
• Season ticket loan
• Cycle to work scheme
• Yoga, run club and social events with other sustainability startups in our co-working space…alongside monthly socials and regular collaboration opportunities with a team that’s passionate, hardworking, and kind.