Lead Full Stack Engineer

We’re on a mission to make it simple and affordable for every home in the UK to be heated and powered by clean, green electricity. Our customers are the installers who are at the forefront of this transition, but who have historically been overlooked and left struggling with outdated, ineffectual software.

Since getting started at beginning of 2024, we’ve grown exponentially, have raised several rounds of funding from top tier VCs, and now support over 500 heat pump installation businesses across the UK.

We’re looking for an exceptional Lead Engineer to help us move faster and go further as we start to expand outside heat pumps.

We’ve started with most challenging but ultimately most important part of the home energy transition: replacing boilers with heat pumps.

Nearly 20% of the UK’s carbon emissions come from heating homes. There is no credible path to net zero without replacing gas and oil boilers — and today, heat pumps are the only scalable alternative with their almost-magical ability to convert 1kW of electricity into 4kW of heat (🤯).

The problem? The installation process is slow, fragmented, and painfully manual. This increases costs for homeowners, limits how fast installation businesses can grow, and makes it almost impossible to offer a heat pump when someone’s boiler breaks down.

We’re fixing this. We’ve built an end-to-end operating system for heat pump installers — from initial enquiry through design and installation to compliance and paperwork. Relative to the best alternatives, Spruce now:

• Halves the time installers spend per job;
• Doubles sales conversion rates; and
• Improves quality, margins, and customer experience.

And we’re only just getting started. With fresh investment and growing demand, we’re now expanding into the rest of the home renewables supply chain – supporting manufacturers and merchants as well as installers, and enabling solar & battery installations alongside heat pumps.

As a Lead Full Stack Engineer, you’ll sit at the intersection of hands-on technical work, team leadership, and product strategy.

You’ll still write a bunch of code — especially the hard, high-leverage parts — but your impact will increasingly come from setting direction, unblocking others, and raising the bar across the team.

You’ll work closely with engineers, designers, and product leadership to ensure we’re building the right things, in the right way, at the right time.

• Own architecture and technical strategy for a core domain or set of systems.
• Design, guide, and build complex, cross-cutting solutions that span multiple parts of the product.
• Write high-leverage code: reference implementations, critical paths, foundational frameworks.
• Lead technical discussions, make trade-offs explicit, and help teams align.
• Mentor senior engineers and develop others into technical leaders.
• Coach engineers in how to make decisions, rather than making every decision yourself.
• Proactively identify scaling risks, bottlenecks, and areas of technical debt — and drive solutions.

Depending on your background, you may:

• Be stepping into your first formal lead role from a senior IC position, or
• Have already led teams successfully and want to stay close to the technical work

Either way, we’ll support you in growing your leadership scope over time.

This is not CRUD-only work. You’ll be working meaningful production problems from day one that blends physical reality, real-world constraints, and serious impact:

• Heat loss modelling and hydronic system design
• 2D and 3D floor-plan tooling using LiDAR and computer vision
• Large-scale data ingestion and geospatial analysis
• Hardware integrations (Bluetooth measurement tools, sensors, monitoring systems)

Our tech stack strives for simplicity, symmetry and efficiency. Our hard problems come from the real world instead of self made architectural problems.

You don’t need to know all of the below but you do need an appetite for full stack mastery and owning the problem end to end.

• Docker, Docker Compose
• Postgre
  
  SQL, PostGIS, Atlas migrations
• Node, Prisma
• React, Typescript, Konva, Tailwind

Requirements

We care less about titles and more about…