Frontend Engineer

Job title: Frontend Engineer

Location: London, UK

Contract type: Permanent employee, full-time

Salary: £55,000 - £60,500 per year

About us

We are a climate analytics nonprofit established in 2021. We provide system modelling data, software and analysis to support energy transition planning and decision-making. We are grant-funded by the Quadrature Climate Foundation, Google.org, Sequoia Climate Foundation, Bloomberg Philanthropies, European Climate Foundation, among others. Our data, software and analysis is used by developers, financiers, planners and think tanks internationally.

At TransitionZero, we understand that diversity is an essential component of a successful team, whether that be diverse ways of thinking, personal or professional backgrounds and skills. We aim to be the most talented nonprofit in our vertical, spearheading innovative data solutions through our culture of inclusivity and adaptability. Now we are looking for a frontend engineer to join our tech team.

Our people are our greatest asset, and the diverse experience, skills and perspectives individuals bring to our organisation are the driving force of our success. We will therefore consider all qualified applicants in the recruitment process as we welcome all the unique qualities and experiences that make you, you.

About the role

TransitionZero is seeking a Front-End React Engineer to develop and enhance the user interface for Scenario Builder, our SaaS-based Energy Systems Modelling tool. Reliable and accessible modelling tools are crucial in accelerating the shift to a net-zero emissions energy system which is why we created Scenario Builder.

Scenario Builder is a crucial resource designed to help stakeholders pinpoint the most impactful actions for reducing energy system emissions across the short, medium, and long term. You'll play a pivotal role in designing and delivering intuitive and interactive front-end experiences that meaningful and tangibly contribute to efforts to decarbonise the energy system.

Responsibilities

• Collaborate with the senior front-end engineer, the rest of the Scenario Builder squad and the wider technology team to deliver new features within Scenario Builder.
• Contribute to front-end direction, architecture and team ways of working.
• Build responsive and accessible components that deliver an excellent user experience across devices and user needs.
• Consistently ship features and improvements with minimal guidance and support from other team members. Collaborate with the team on larger projects.
• Participate actively in code reviews and provide constructive feedback to enhance code quality.
• Help improve our test coverage and system reliability through thoughtful testing practices.
• Contribute to troubleshooting and resolving technical issues as they arise.
• Support technical documentation and internal knowledge-sharing initiatives.
• Participate in Neptune days; helping to innovate and build solutions to projects and initiatives suggested by colleagues.

About you

We’re looking for a product-focused front-end engineer with a sharp eye for detail and a strong appreciation for design. You’ll join a small, fast-moving team building interfaces that feel effortless — not just functional. You’ll collaborate closely with backend engineers and product managers to ship polished, accessible, and performant experiences.

You’ll work with:

• Next.js + TypeScript for dynamic apps
• Radix UI, shadcn/ui, and Tailwind CSS for styling and components
• React Query for data fetching
• Framer Motion for animation
• Vitest for testing
• RESTful APIs

Skills & Experience

Essential

• Deep experience with React, Next.js, Tailwind CSS, and React Query
• Strong knowledge of TypeScript and confidence building type-safe component APIs
• Proven track record of product-led development — you think in UX, not just features
• Experience building and maintaining reusable component systems
• Solid understanding of accessibility and frontend performance
• High attention to visual and interaction detail — you notice and care about the small things
• Familiarity with testing tools like Vitest, Playwright, or React Testing Library

Beneficial

• Experience rendering high-performance charts (Chart.js, Recharts, D3, or custom canvas/SVG)
• Backend familiarity with Node.js, or Python
• Interest in AI-assisted development and workflows (Cursor, Copilot, ChatGPT, etc.)
• Comfort working with design tools (e.g. Figma) and cross-functional design-engineering collaboration

Salary & Benefits

• Competitive salary based on experience
• Enhanced competitive pension scheme- auto-enrollment from day 1
• 25 days annual leave (excluding UK public holidays) and an additional discretionary days off such as over the festive period
• 20 days annual allowance to work from anywhere in the world
• Hybrid working and core working hours model
• Allowance to set up your home office
• Annual budget and dedicated leave time for relevant training courses
• Enhanced gender-neutral parental leave (16 weeks fully paid)
• Private healthcare following successful completion of the probation period
• Yearly team offsites

Our commitment to diversity, equity, and inclusion

Studies have shown that some people from marginalised or underrepresented groups are less likely to apply to a role unless they meet all of the hiring guidelines or qualifications. Whoever you are, even if you don't meet all of the criteria, if you can demonstrate a variety of skills and experience relevant to this role, we encourage you to apply as you might just be the candidate we hire! At TransitionZero, we're looking for people who are genuinely passionate about what they do, and we welcome all people, regardless of their background.

If you would like to discuss any reasonable adjustments to the application or hiring process that may better facilitate your participation, please contact our People Team (people@transitionzero.org) for an informal chat. We will make every effort to respond to your request for assistance as soon as possible.