Fullstack Software Developer - Mid level London, United Kingdom

Heat Geek Ltd; Greater London; On-site; GBP 55,000 - 70,000; Full time

Benefits offered by this job

Heat pump installation aid

Equity in company

Private medical & dental insurance

Learning & development budget

Annual summer retreat

Cycle to work scheme

Yoga and social events

Job summary

Heat Geek Ltd in London is seeking a Mid-level Fullstack Software Developer to own features across frontend, backend and infra, shipping production‑ready software that actually helps users and makes an impact.

You will collaborate with Product and Tech teams to balance technical quality with commercial pragmatism and learn new concepts as needed. This is a coding‑first role in a fast-growing climate-tech company.

Qualifications

• Mid-level experience as a fullstack software engineer.
• Proven ability to ship and maintain production software.
• Demonstrated pragmatism – know when to refactor, ship, or leave things alone.
• Quick learner who can pick up new concepts and technologies efficiently.
• Strong ownership mindset – take initiative to fix issues.
• Clear communication skills and collaboration mentality.

Responsibilities

• Own and support features and systems end-to-end, from discovery through to production and iteration.
• Build, maintain, and improve production-ready frontend and backend systems.
• Work hands-on in the codebase – this is a coding-first role.
• Collaborate with Product and Tech teams to solve real user problems.
• Quickly pick up new concepts, technologies, and domain knowledge as needed.
• Contribute to technical direction and raise the quality bar across the team.

Job description

Fullstack Software Developer - Mid level

London, United Kingdom

Type: Full-time

Reports to: Co-founder, CEO

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. As of July 2026 we have prevented 2,600,000 tonnes of carbon from entering our atmosphere, and we're not stopping 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. – And we need passionate, talented, hard‑working people to be a part of this journey.

Your Mission

Our Heat Geek community is excited to bring a Fullstack Software Developer into the team – a role that’s critical to how we grow and scale our platform.

This is your chance to own meaningful product areas end‑to‑end, working across frontend, backend, and infrastructure to ship software that actually runs, actually helps users, and actually makes an impact. If you love the idea of steering real product decisions, getting stuck into code, and balancing technical quality with commercial pragmatism, this role is for you.

If you’re reading this and it resonates, we know you could do this job anywhere — but we want you to do it HERE, with us, because we need persevering teammates who care deeply about making a real difference in the world.

• Own and support features and systems end‑to‑end, from discovery through to production and iteration
• Build, maintain, and improve production‑ready frontend and backend systems
• Work hands‑on in the codebase – this is a coding‑first role
• Collaborate closely with the existing Product and Tech teams to solve real user problems
• Quickly pick up new concepts, technologies, and domain knowledge when needed
• Contribute to technical direction and raise the quality bar of the entire team’s output through example, not ceremony
• Help ensure the platform runs, scales, and supports Heat Geek’s mission as we grow

Candidate Requirements

• Mid‑level experience as a fullstack software engineer, with strong hands‑on coding ability
• Proven ability to ship and maintain production software
• Demonstrated pragmatism – you have a strong sense of when to refactor, when to ship, and when to leave things alone
• Quick learner who can pick up new concepts and technologies efficiently
• Strong ownership mindset – you don’t wait to be told what to fix
• Clear communication skills and collaboration mentality

It’s a bonus if you have…

• Experience with Django
• Real comfort across the full stack, happily spending time in both the frontend and backend
• Experience with cloud / infrastructure, ideally GCP
• Industry experience in renewable energy, heat pumps, utilities, or construction
• Been in product‑focused engineering environments
• Worked in a startup or scale‑up environment

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. And don’t get us started on the epic view!

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
• Season train ticket loan
• Cycle to work scheme
• Annual retreat with the whole Heat Geek team
• 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.

By submitting your application, you agree that Heat Geek may process your personal data for recruitment purposes in accordance with UK GDPR. If your application is unsuccessful, we may retain your data in our applicant tracking system for up to six months after the role closes to consider you for future opportunities. Your data will be handled in accordance with GDPR data protection laws. - Please read our full privacy policy here: https://www.heatgeek.com/tncs/privacy-policy

By checking this box, I agree to allow Heat Geek to retain my data for future opportunities for employment for up to 180 days after the conclusion of consideration of my current application for employment.