Design Engineer

Since early 2024, we've gone from 0 to over 900 customers, succeeding where many have tried and failed before. We have a big mission: to make it wildly easier and more profitable to run and grow a renewables installation business, and through that to make a real dent in the world's carbon emissions and a far better experience for homeowners.

We're now looking for a Design Engineer who wants to design & ship exceptional outcomes for users. Most of our product is a front end over hard physics (heat-loss calculations, hydronic design, LiDAR floor plans, compliance that has to be right), used by installers on a phone, with no signal, in a hurry. Making that feel simple is a design problem and an engineering problem at the same time, and this role sits right on that seam.

🌲 About Spruce

• Almost 20% of the UK's carbon emissions comes from heating homes – there's simply no way to reach net zero without phasing out gas and oil boilers. Right now the only serious alternative is heat pumps, with their almost-magical ability to turn 1 kW of electricity into 3-5 kW of heat (🤯). But the heat pump installation journey is slow, inefficient, and just so painful. This makes it hard for existing installers to grow their businesses and puts off gas engineers from starting to do heat pumps. Perhaps most critically, it means you can't currently offer a heat pump when someone's boiler breaks and they urgently need heating.

• We're fixing this. We've built a platform for heat pump installers to manage the whole installation journey from initial enquiry through to final compliance paperwork, freeing up their time to focus on what really matters: doing high-quality installations, providing great customer service, and scaling their business. Despite only getting started at the beginning of 2024, we're having a massive impact on installation businesses, suppliers, and manufacturers across the UK: halving the time they spend on each job and doubling their sales conversion rates.

• We raised a chunky Seed round last year from top-tier investors and this year have grown the team 3x and revenue 4x. We've expanded into Ireland, are launching an end-to-end solar and battery product in November, and are increasingly becoming the operating system for the whole home renewables supply chain. If you can picture a combination of ServiceTitan, Procore, and AutoCAD, you might get a sense of where we're headed…

🥖 The role

You'll own how the product looks, feels and behaves wherever installers use it, from the first sketch to the shipped feature. Installers only adopt Spruce if it's easy to use on a real job, and adoption is what drives our growth. That puts your work at the centre of the business. Day-to-day you'll be:

• Designing and shipping – You'll take a flow from rough idea all the way to production, prototyping in whatever gets you to an answer fastest (often code, sometimes Figma or a sketch), and testing with installers as you go. The gap between "we should fix this" and "it's fixed" is often a day.

• Owning the interaction layer – You'll build and look after the component library and the patterns underneath it: motion, loading and empty states, touch targets that still work with gloves on. The small things that make a complex tool feel simple.

• Building the parts that are hard to get right – The canvas-based floor plan and system design tools, the offline survey app (incl. LiDAR), the proposals homeowners see. These are the parts where the UI is the product, and where we've got the most still to build.

• Raising the bar on everything we ship – You'll work closely with our product designers and developers, pairing on their work and reviewing it, so the quality of what you build rubs off on the rest of the product.

• Spending time with installers – You'll go out on site, watch how the product actually gets used, then come back and change it.

You'll report to Steph, our co-founder and CPO (she’s pretty awesome) and you’ll work alongside Dan & Arron who’ve cooked up some incredible work in their time so far.

🫵 About you

We look for the same five things in everyone at Spruce: curiosity; intense drive, ambition and work ethic; a high degree of personal agency and ownership; deep humility and a growth mindset; and excellent craft. You might currently call yourself a designer who ships, a front-end engineer with strong design instincts, or already a design engineer. We're looking for 3+ years of experience (and potentially a lot more) designing and building product UI, ideally in a startup or a fast-paced, impact-focussed team. We'd love to speak with you if you have:

• Real taste, and shipped work to prove it – You can show us production UI you designed and built, and talk about why the details are the way they are. Work you'd happily put next to the best-crafted B2B products out there.

• Strong design craft, and a real appetite for code – You're a strong designer first. You don't need to be a front-end engineer, and you might well ship with Cursor or Claude Code, but you want to understand the code you're shipping. Bonus for React and TypeScript depth, canvas/WebGL, animation, or complex state on mobile.

• A prototyping instinct – You'd rather build a rough version and test it than argue about it in a doc. You're comfortable with things being imperfect in front of users.

• Systems thinking – You enjoy the structure of a good component library and understand that consistency is what lets a small team ship fast. You also know when to slow down first: you value time spent on lo-fi wireframes and on understanding the data model before anything gets polished.

• Curiosity about the domain – You want to understand how heating systems, solar and battery actually work, and you pick up technical detail fast. By the end of week two you'll be arguing about the best way to show a homeowner their solar self-consumption.

🌟 Our offer

• 💰 £60-110k salary, depending on experience and location

• 🍰 Meaningful slice of equity (options) in the company

• 🏖️ 33 days holiday (25 plus bank holidays) and opportunity to work from abroad for another 30 days each year

• 🏡 Hybrid working: 2–3 days in-person a week (London or Bristol), with full-team meetups every fortnight

• 🏥 Private Medical Cover (Vitality)

• 👧 Workplace Nursery Benefit scheme (YellowNest)

• 🧑‍🍼 Enhanced Parental Leave

• 🚲 Cycle to Work scheme

• 👨‍👩‍👧‍👦 Brilliant team to learn from and massive opportunity to grow

🧑‍💻 Working at Spruce

• We're currently a close-knit team of 34, split between London and Bristol. We spend 2-3 days each week working together in-person in both locations, and get everyone together every fortnight.

• You'll have genuine influence from day one. The best idea wins regardless of seniority. We expect you to challenge everything, ask "why?" multiple levels deep, and push back when something doesn't make sense.

• We want everyone to spend time with installers on-site, feel their pain points, then be able to rapidly suggest and implement solutions based on real feedback rather than assumptions. This is clearly particularly important for this role but you'll be surrounded by a whole team who are also close to our customers.

• We move fast and ship imperfect things, learning from users rather than trying to perfect in isolation. When things break, we focus on how we fix it, what we can learn, and never blame. You'll own your outcomes whilst knowing the team has your back.

• Feedback is constant, direct, and kind. We'll tell you when something isn't working and expect the same honesty (and empathy) back.