Senior Frontend Engineer / Full Stack Product Engineer

Senior Frontend Engineer / Full Stack Product Engineer - Energy

About the Role

Our client is hiring a Frontend Engineer / Full Stack Product Engineer to help build the software that their customers interact with directly, as they continue to scale their product and technology function. We have already recruited 3 individuals to the company and are pleased to be supporting them again on this key hire.

The role is based in Mayfair, London and operates on a hybrid basis, ideally with 3 days per week in the office initially.

This is not a standard frontend role. The business is looking for someone with strong frontend capability, but also enough full stack knowledge to work closely with leadership on the wider software build. They need someone who can operate with a high level of ownership, move quickly, and help shape both product and engineering direction in a growing business.

Senior Frontend Engineer / Full Stack Product Engineer - Role Purpose

We are looking for a Frontend Engineer / Full Stack Product Engineer to build the software that customers interact with directly, while also working in parallel with the wider software team on broader technical delivery.

This person will be responsible for turning complex operational and commercial data into interfaces that are clear, reliable, and genuinely useful. The product includes energy-related workflows such as metering, billing, consumption, reporting, and asset performance, but the client is also very open to candidates who have built in similarly complex environments such as trading or fintech.

You will own key customer-facing product areas, work closely with data and backend teams, engage directly with stakeholders, and help decide what to build, how to build it, and how to improve it over time.

They are especially keen to find someone enthusiastic about AI and modern AI-powered development tools, as well as someone open to integrating AI agents and automation into the product over time. This is a highly visible role within a small team, so a junior mindset is unlikely to be the right fit. They need someone confident operating without heavy direction.

Senior Frontend Engineer / Full Stack Product Engineer - Key Responsibilities

1. Build Customer Platforms

• Design and build the interfaces through which customers view and interact with complex business data, including consumption, billing, operational workflows, reporting, and asset-related information
• Take ownership of the frontend codebase, defining architecture, component structure, and engineering standards
• Work closely with backend and data teams to create clean API integrations and iterate on UX based on customer feedback

2. Work Across the Stack

• Bring enough backend knowledge to work effectively alongside leadership on the software side
• Read APIs confidently, understand schemas, and contribute to broader technical decision-making
• Support end-to-end product development rather than operating as a purely UI-focused engineer

4. Help Shape Engineering Practice

• Set up component libraries, testing approaches, and development conventions that the team will build on
• Help create an environment that is easy to onboard into as the team and product grow
• Work closely with the founding team to prioritise effectively, balancing speed of delivery with durability

5. Embrace AI and Modern Development Tools

• Use AI-powered programming tools to improve speed, quality, and engineering output
• Show willingness to work with AI and integrate agent-based workflows into software where useful
• Contribute to a forward-thinking engineering culture that embraces modern tooling in a practical way
• Stay open to new ways of building software in a fast-evolving technical environment

6. Stay Close to the Customer and the Market

• Engage directly with customers and internal stakeholders to understand how the product is being used and where it can improve
• Build a working understanding of the UK energy market and wider commercial context
• Bring relevant ideas from previous sectors such as energy, trading, or fintech into the product

What We’re Looking For

• Strong frontend fundamentals across HTML, CSS, JavaScript, and a modern framework, ideally React
• A track record of shipping customer-facing products and being able to demonstrate their impact
• Strong product instinct, with the ability to think beyond the brief and focus on what users actually need
• Enough backend knowledge to work effectively across the stack and contribute beyond pure UI delivery
• Comfortable operating with limited direction in a fast-moving environment
• Someone who enjoys ownership, pace, and building from the ground up
• Genuine enthusiasm for AI, modern engineering tools, and the integration of AI into software products

Nice to Have

• 3-5+ years building customer-facing software in a product-led, startup, or scale-up environment
• Experience with data visualisation libraries and presenting large, complex datasets clearly
• Exposure to energy, trading, fintech, utilities, or another technically complex B2B sector
• Experience setting up a frontend codebase from scratch
• Enough backend familiarity to read APIs, spot schema issues, and work effectively across the stack
• Experience contributing to architecture and technical decision-making, not just implementation

What You’ll Get

• A highly owned role at the centre of what customers actually see and use
• The opportunity to shape a product from an early stage into something customers rely on
• Close collaboration with a small leadership team, with direct input into product and technical direction
• The chance to build expertise across energy data, customer software, AI-enabled development, and complex product delivery
• Long-term scope to grow with the company as its customer base and platform expand

Why Join?

This Frontend Engineer / Full Stack Product Engineer opportunity offers the chance to join a business at an exciting stage of growth, where one very strong hire can have a major impact.