Senior Design Engineer

Payaca Ltd.; West of England; Hybrid; GBP 70,000 - 95,000; Full time

Benefits offered by this job

33 days holiday

Regular team away-days and socials

Free breakfast and snacks

Free on-site gym

Job summary

Payaca Ltd. in Bristol is seeking a Senior Design Engineer to own how our product looks and feels in a medium that ships. You’ll focus on the design system, visual consistency, and user interaction for installers and office staff.

You’ll work with product engineers, designers, and AI agents to ship high‑quality, repeat‑use software across web and mobile. Office‑first, Bristol-based with fast decision cycles and collaboration.

Qualifications

• 4+ years shipping production frontend using TypeScript, React and CSS.
• Proven design system ownership from concept to production.
• Experience collaborating with designers and engineers, using AI tools when appropriate.

Responsibilities

• Take hardest design problems end to end: shape the problem, design, build, ship, and measure impact.
• Grow and mature the design system for desktop, mobile, and offline patterns.
• Raise the floor on quality across flows and enable cross‑team collaboration.
• Design for varied usage: desktop web, mobile web, and offline-first mobile.
• Collaborate with product engineers on the screens being built.
• Leverage agents to handle repetitive work, focusing your time on judgment.
• Set and uphold patterns and quality through review and hands‑on work.
• Partner with AI tooling to accelerate delivery while maintaining ownership.

Skills

Frontend shipping

TypeScript

React

CSS

Visual design

AI tooling

Figma

Design system

Tools

Figma

Claude Code

GitHub Copilot

Job description

Ready to build software that's accelerating the clean-energy rollout? We're looking for a Senior Design Engineer to own how our product looks and feels, from our small but mighty team in Bristol.

Payaca is the operating system for clean-energy installers, the businesses putting solar, heat pumps, battery storage and EV chargers on homes and businesses across the UK and US. We bring quoting, scheduling, job management, invoicing and compliance into one place built for how these companies actually work.

These are growing businesses that have outgrown spreadsheets and generic trade software. We give them tools designed for their world, so they can win more work, run more efficiently, and scale.

Clean energy is being installed faster than ever, and the installers doing that work are at the centre of it. The better they run, the faster it happens.

About the role

This is not a Frontend Engineer with a new job title, and it isn't a designer who prototypes in code. A Design Engineer designs in the medium the product actually ships in. You'll prefer making visual and interaction decisions in the platform they'll be built in, because designing for the web in Figma duplicates effort when you're comfortable implement it too.

Our users are not browsing. They are installers, engineers and office staff running a business inside Payaca all day. That's the design brief: repeat-use business critical software where a saved click compounds hundreds of times a day.

What you'll do

• Take our hardest design problems end to end: shape the problem, decide the design, build it, ship it, and watch how it lands in production
• Grow our design system, balancing consistency with expanding requirements
• Mature our design system, enabling agents and devs to work efficiently across the product
• Raise the floor on quality across the product - the flows that work but feel like hard work
• Design for different usage patterns with varying constraints: back office staff on desktop web, their customers on mobile web, and field engineers on offline first mobile
• Pair with product engineers on the screens they're building, so taste spreads rather than bottlenecks on you
• Use agents to do the volume work - variants, sweeps, migrations - so your own time goes on judgement
• Set the patterns and the bar, through review and through the work itself

Frontend

React, React Native/Expo, TypeScript, Tailwind, Figma

Infrastructure

Google Cloud Run, Firebase Hosting, Terraform, CircleCI

Monorepo, pnpm, MacBook Pro

AI tools

Claude Code, Claude Agent SDK, Paperclip, Wispr Flow, GitHub Copilot

What we're looking for

• 4+ years shipping production frontend, strong in TypeScript, React and CSS
• Visual design taste you can point at - work you designed and built yourself, in the hands of real users
• A track record of owning interface work from a vague brief through to production, resolving most of the ambiguity yourself
• 3+ months getting real work done with AI coding agents, delegating meaningful chunks rather than autocompleting
• Enough range to follow a change past the UI when it needs API or data-model shape to work properly
• A high bar for quality, and the discipline to never merge code you can't stand behind, whether you or an agent wrote it
• A healthy curiosity about clean-energy installers and the businesses they run

This probably isn't for you if

• You want to work on the design system full time, rather than on the product with the design system as a means
• You need research and sign-off before you can start building
• You need it perfect before it ships
• You need someone else to break the work down and sequence it for you

How we work

Where we work

We're an office-first team based in central Bristol. Our office is a short walk from the harbourside, green space, and several food markets.

The whole engineering team sits together, so getting unblocked is quick and sharing ideas is easy. We favour instant, on the spot collaboration over Slack messages and recurring meetings.

You manage your own time, too. Errands, appointments and life admin during the day don't need approval or apology, as long as the work gets done.

Our philosophy on AI

AI is not a side project here, it is how we work. We've built an organisation of AI agents that runs alongside the human team. They sync our data, handle the tedious updates that used to eat whole afternoons, surface what actually needs a human, and even coach us with feedback on our own work. The result is that you spend your time on the things that genuinely need you, not on admin a machine should be doing.

You'll be expected to use these tools every day, to lean on them hard, push their limits, and help us find the next thing they can take off our plates. We're genuinely at the edge of AI tooling adoption and we move fast. If that excites you, you'll love it here. If the idea of working this closely with AI makes you uncomfortable, this honestly isn't the place for you, and that's okay.

In engineering, agent-driven development is the default. We delegate real, multi-step work to coding agents, manage their context carefully, and often run several at once. When an agent goes off piste, we don't just step in, we ask how can we give it the context to get it right next time. Hand-writing code line by line is increasingly the exception rather than the rule, and the nature of the job has shifted from doing the work to directing and verifying it.

That raises the bar on judgement rather than lowering it. You're accountable for everything that ships under your name, including the parts an agent produced that you didn't type yourself. The rule is simple and applies to everyone: you never merge what you can't defend. If you don't yet understand it, you build that understanding, add verification you trust, or elevate, before it goes out. We've found that this way of working produces not just better software, but better engineers as we learn on the job more than before.

Ownership

We're a small team, so you'll have real ownership of your work and the freedom and responsibility to make the key decisions yourself.

33 days holiday (including bank holidays)

Regular team away-days and socials

Flexibility when needed

Free breakfast and snacks, a chest freezer full of ice cream for the summer, and team lunches in our Bristol office

Free on-site gym

1. 1

   Culture and experience (1 hour interview)

   Here we're looking to learn about you and your working style. It's also a great opportunity for you to learn more about us and the way we work

2. 2

   Technical take-home (~2 hours + 45-minute interview)

   You'll receive a dummy GitHub repository and a feature request to implement. We want to see how you work and how you approach a problem using your preferred tools, agents included. We'll then discuss your solution and its trade-offs. We'll provide a token budget for the assignment.

We value diverse perspectives and encourage you to apply even if you don't meet every single requirement.