Senior Frontend Engineer

Socket.dev; London (KY); Hybrid; USD 121,000 - 162,000; Full time

Job summary

Octopus Energy Group is seeking a Senior Frontend Engineer to join the Flexibility team in a hybrid-capable role based in the UK. You will lead frontend direction, build customer-facing journeys for low carbon tech, and collaborate with design systems and mobile teams to deliver scalable, accessible experiences.

You will own a broad stack with React, TypeScript, Next.js, and GraphQL, shaping high-traffic web interfaces used by millions while enabling rapid responses to new opportunities.

Qualifications

• 5+ years of experience with frontend stack and React-based technologies.
• Ability to transform problems into robust frontend solutions.
• Confidence owning the full development cycle from requirements to deployment.
• Experience tackling large-scale tasks independently and delivering impact.
• Empathetic approach to delegation and collaboration within teams.
• Ability to build accessible, inclusive websites meeting strong guidelines.
• Proven track record of scalable, performant sites handling high traffic.
• Desirable: energy domain knowledge.

Responsibilities

• Act as the flexibility team's first frontend engineer, establishing frontend capability and direction.
• Build and own a range of customer-facing journeys enabling onboarding, control, and analysis of low carbon tech.
• Create internal-facing interfaces for stakeholders and experimental prototypes.
• Coordinate with mobile teams by providing WebViews for customer journeys.
• Integrate designs into the Coral design system in collaboration with design teams.
• Participate in product discovery with Product Manager and stakeholders.
• Develop highly reusable interfaces to enable rapid response to new opportunities.

Skills

Frontend development

Frontend architecture

Accessibility

Performance optimization

Collaboration

Tools

React

TypeScript

Next.js

GraphQL

React Testing Library

Vitest

MSW

Job description

We're making energy fair, clean, and simple for all using technology.

Octopus Energy started with a bold idea: to build Britain’s first truly digital energy supplier. By combining world‑class tech with brilliant humans who care deeply about customers and driving the renewable energy transition, we made it happen and in 2025, we became Britain’s largest energy supplier.

Octopus Energy Group is a global energy transition collective. 10 businesses working across 4 continents to tackle energy transformation at nearly every front.

And we constantly push to make energy better. Tirelessly campaigning for fair protections for customers. And building innovative technologies that forge a path to a green energy system.

We’re made up of 10,000+ authentic, committed people working around the world on stuff you'd never expect. We're united by a shared goal: to drive the global green energy revolution. Read our Spotlight series to meet some of the team.

We are looking for a Senior Frontend Engineer to join our Flexibility team.

The Flexibility team was established in early 2026, and has been growing throughout the year. The team is focused on greenfield opportunities at the cutting edge of Octopus' flexibility strategy, and aims to enable rapid response to global flex opportunities.

They are building the next generation of products and tools to make energy more flexible. These include our flagship Intelligent Octopus product automating demand shift for 300,000 customers with electric cars, home batteries or smart heating devices, saving 2 million customers money through Saving Sessions and Free Electricity Sessions, and managing 568MW of large grid‑scale batteries to balance the system. The team develops products that are used by millions of customers, helping boost renewables use and decarbonise energy systems worldwide.

We embrace flat hierarchies and an open, agile culture that fosters innovation, flexibility, and creativity.

We don’t hang our personalities up with our coats and nor should you. At Octopus, we hire great people who get stuff done, all whilst being themselves.

If this sounds exciting, we’d love to chat.

What you'll do

• Acting as the flexibility team’s first frontend engineer, establish the team’s frontend capability, lead the team’s frontend technical direction and represent the team to the cross-team community of frontend engineers
• Build and own a diverse range of customer‑facing user journeys, enabling customers to onboard, control, and analyse their low carbon tech
• Build and own internal‑facing interfaces for stakeholder‑collaborators and experimental prototypes
• Interface with established mobile teams by providing WebViews for emerging mobile customer journeys
• Collaborate with our internal design team to integrate our designs into the wider Octopus design system ‘Coral’
• Carry out product discovery by working closely with our Product Manager and stakeholders from across the organisation
• Build highly reusable interfaces that enable rapid response to new opportunities

What you'll have

• 5+ years of experience with our stack (listed below)
• Experience taking problems, rather than strict guidelines, and developing strong solutions
• Confidence owning the development cycle (request, requirements gathering, technical proposal, technical execution, deployment and monitoring.)
• Confidence tackling large‑scale tasks individually
• An empathetic approach to delegating work and collaborating with others
• The ability to develop websites that meet strong accessibility guidelines
• Experience building scalable, performant sites that handle high levels of traffic well
• Desirable: energy domain knowledge

Our stack

• React (required)
• TypeScript (required)
• Next.js on Vercel (desirable)
• GraphQL w/ Tanstack Query (desirable)
• React Testing Library & vitest and/or msw (desirable)

We have a preference for candidates who can work hybrid from our London office, but we're open to fully remote candidates (you do need to be based in the UK).

Why else you'll love it here

Wondering what the salary for this role is? Just ask us! On a call with one of our recruiters it's something we always cover as we genuinely want to match your experience with the correct salary. The reason why we don't advertise is because we honestly have a degree of flexibility and would never want salary to be a reason why someone doesn't apply to Octopus - what's more important to us is finding the right octofit!

Octopus Energy Group is a unique culture. An organisation where people learn, decide, and build quicker. Where people work with autonomy, alongside a wide range of amazing co‑owners, on projects that break new ground. We want your hard work to be rewarded with perks you actually care about! We were recently named the UK's top company to work for, and we ranked in the top ten in the Sunday Times Best Places to Work 2024. Our Group CEO, Greg has recorded a podcast about our culture and how we empower our people. We’ve also been placed in the top 10 companies for senior leadership

Visit our UK perks hub - Octopus Employee Benefits

If this sounds like you then we'd love to hear from you, tell us what you care about, why Octopus feels right and most importantly, bring us the real you! Applying for jobs can be a bit scary so have a nose through some of our tips first

P.S. Our process usually takes up to 4 weeks, but we’ll always do our best to flex around what works for you. Along the way, you’ll chat with our recruitment team and your Recruiter will help you throughout different stages. Got any burning questions before then? Drop us a message at [e-mail] and we’d love to help!

Are you ready for a career with us? We want to ensure you have all the tools and environment you need to unleash your potential. Need any specific accommodations? Whether you require specific accommodations or have a unique preference, let us know, and we'll do what we can to customise your interview process for comfort and maximum magic!

Studies have shown that some groups of people, like women, are less likely to apply to a role unless they meet 100% of the job requirements. Whoever you are, if you like one of our jobs, we encourage you to apply as you might just be the candidate we hire. Across Octopus, we're looking for genuinely decent people who are honest and empathetic. Our people are our strongest asset and the unique skills and perspectives people bring to the team are the driving force of our success. As an equal opportunity employer, we do not discriminate on the basis of any protected attribute. Our commitment is to provide equal opportunities, an inclusive work environment, and fairness for everyone.