Junior Software Developer Jobs in London, KY (NOW HIRING)

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’re looking for a Senior Software Engineer to join as a founding member of our new AI team.

You'll help Octopus move past ad-hoc, "vibe-coded" AI experiments and build a safe, scalable, and lightweight AI capability from the ground up.

In this role you will help build our central developer tools and production gates, work directly with business teams such as Software Engineering, Operations, Services, and Finance to co‑build live features and accelerate local teams.

• Embed temporarily within cross‑functional business teams (e.g. Services, Ops, Finance) to co‑build high‑impact AI features directly inside their domain codebases and smooth out day‑to‑day bottlenecks
• Design and build internal developer tools, standard templates, and pipeline gates (security, technical standards, tone, and performance checks) in Python to simplify how teams across Octopus safely integrate AI into their software
• Establish clear guardrails, security standards, and production pathways to turn quick, hacky AI prototypes into secure, scalable, and well‑architected systems
• Engage directly with both technical and non‑technical stakeholders across business units to help map out fuzzy operational problems, understand pain points, and design practical AI‑augmented workflows
• Collaborate closely with the Data team to ensure data flows securely and effectively into front‑facing AI tools and applications
• Provide hands‑on pairing, mentorship, and technical guidance to local teams during embedded rotations, ensuring they can independently maintain and expand the technology built together post‑handoff
• Gather insights from on‑the‑ground embedded deployments to feed real‑world requirements back into our central prototyping tools, patterns, and frameworks

• A strong technical background in backend engineering (with deep fluency in Python/Django), a solid understanding of system design, and a genuine interest in Developer Experience (DX) and system reliability
• Hands‑on familiarity and curiosity with modern AI toolchains, LLM integrations, retrieval patterns, and rapid prototyping frameworks, alongside the ability to audit AI‑generated code
• Strong stakeholder management and communication skills, with a proven ability to collaborate effectively across both deeply technical tech teams and non‑technical business partners
• A pragmatic builder mindset that prioritises shipping fast, practical value to solve immediate operational friction over over‑engineering complex architectures
• Excellent collaborative and coaching skills, with demonstrated experience in pair programming, mentoring, or elevating team capability, combined with high accountability and a low‑ego approach to handing off projects
• Comfort working in a fast‑paced, high‑autonomy environment where you can navigate context‑switching between projects and help shape workflows from the ground up

• 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

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.