Senior Software Engineer (AI Tooling)

Team: Agentic Engineering (Claude Rollout)

Location: Hub Based - Hybrid for all

Salary banding: £55,000 - £85,000

Experience: Expert

Working pattern: Full-Time

Reporting to: Delivery & Growth Lead

Sponsorship: Unfortunately we are unable to offer sponsorship for this role.

This role in 3 words: Build, Collaborate, Deliver

Top 3 qualities for this role: Communication, Delivery Expertise, Amplification

Where You'll Work: Depending on the needs of your business area, we expect hub based people to be in the office at least once a week, and to go to the company Connection events in-person. You'll be assigned to the closest one of our three hub offices, Bristol, Glasgow, or London; unless your role requires field-based work. Each hub has accessible spaces to park your laptop, is designed to inspire people, help them connect and bring big ideas to life.

About the Company: At the company, we are on a mission to solve one of humanity's biggest challenges, the climate crisis. And we know it takes all of us to change the world. That's why we need diverse people from all abilities, gender identities, ethnicities, ages, sexual orientations, life experiences and backgrounds to join us.

Teamworking for the Planet: Everything we do here spins around Plan Zero. So, naturally, the team you'll be joining plays a gigantic role in making that happen.

Role Overview: As a Senior Software Engineer, you will own the end-to-end development of complex systems and features that are core to our business. You will lead technical initiatives, make critical design decisions and mentor engineers to elevate the team's capabilities. Your expertise will be the driving force that ensures we build scalable, high-quality software that pushes our company forward. This role involves building an elegant, scalable and secure AI tooling ecosystem for all the engineering teams at the company. Your role is pivotal in shaping the architecture of our Model Context Protocol (MCP) servers, security controls and plugin ecosystem. This is an opportunity to solve complex challenges, develop practical agentic tooling being used at an enterprise scale and deliver work that truly matters to our internal developers.

Your Key Outcomes:

• Technical Leadership & Architecture: Drive the architectural vision for key features, designing robust, scalable systems and contributing to the technical roadmap to influence the future direction of the product.
• Engineering Excellence & Quality: Champion best practices by writing clean, efficient code, leading rigorous code reviews and implementing comprehensive automated testing to ensure high-quality, performant tooling in an exciting new field.
• Mentorship & Team Growth: Lead and mentor other engineers, fostering a culture of continuous learning and collaboration through knowledge sharing, technical discussions and constructive feedback.
• Project Execution & Delivery: Translate complex projects into clear, executable tasks within an Agile framework, proactively resolving blockers to ensure the timely and efficient delivery of team commitments.
• Community & Knowledge Sharing: Actively contribute to the wider engineering community by leading discussions, sharing expertise through documentation and workshops, and driving the exchange of best practices.

Qualities & Experience:

• Professional Experience: Significant hands‑on experience developing software in an agile environment, with a proven track record of delivering high-quality, clean code.
• Backend & Architecture: Expertise in designing and building scalable microservices‑based architectures using languages like Node.js, Python and TypeScript.
• AI Tooling & Ecosystems: Proven experience or strong understanding of AI development tools (like Claude Code), Model Context Protocol (MCP), LLM integration and prompt engineering.
• Cloud & DevOps: Hands‑on experience with cloud platforms (GCP, AWS), containerization (Docker, Kubernetes) and modern CI/CD practices.
• Frontend Development: Proficiency in modern frontend frameworks such as React.js and/or React Native.
• Leadership & Mentorship: Proven ability to lead technical initiatives and mentor other engineers, fostering a culture of technical excellence.
• Collaboration & Problem‑Solving: Excellent communication and analytical skills, with the ability to thrive in a high‑ownership, collaborative team environment.

Benefits & Compensation: We keep our pay ranges broad on purpose to give us and you flexibility to match your experience to our zero carbon mission. You'll be eligible for an on-target bonus of 15%. We have one the company bonus plan that focuses on the collective performance of our people to deliver our Plan Zero goal. We also offer plenty of green benefits and progressive policies to help you feel like you belong at the company, and there's flex pay. We'll give you 9% Flex Pay on top of your salary – 4% of this is auto‑enrolled into your pension and the remaining 5% is yours to do what you like with. You can use this to buy from our extensive range of flexible benefits, including our green benefits which we've put at the heart of our offering, add to your pension or even take it as cash.

Here's a taster of what's on offer:

• For starters, you get 34 days of holiday (including bank holidays).
• Health: With benefits like a healthcare cash plan or private medical insurance depending on your career level, critical illness cover, life assurance, health assessments and more.
• Wellbeing: With gym membership, travel insurance, workplace ISA, will writing services, dental insurance and more.
• Lifestyle: With extra holiday buying, discount dining, home & tech loans, and supporting your favourite charities with give-as-you-earn donations.
• Home: Get up to £400 towards any the company Energy plan, plus great discounts on solar, smart thermostats and EV chargers.
• Commute: Nab a great deal on ultra-low emission car leasing, plus our cycle to work scheme and public transport season ticket loans.

Belonging: We need to listen to each other's experiences and find ways to build a truly inclusive and diverse workplace. We have 8 Belonging Networks at the company. Led by our people, for our people – so when you join the company, you can play a part – big or small – with any of the Networks. It's up to you.

Apply: We'd be thrilled if you tick off all our boxes, yet we also believe it's just as important we tick off all of yours. And if you think you have most of what we're looking for but not every single thing, go ahead and hit apply. We'd still love to hear from you! If you have any additional requirements, there's a space to let us know on the application form; we want to make the process as easy and comfortable for you as possible.