Backend Engineer

Octopus Energy · London, England

HybridFull Time Mid Level Software & Technology

Posted August 19, 2026·Closes October 31, 2026

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About the Role

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 Backend Engineers (mid level) to join our Devices team and Low Carbon Tech team.

Devices: Since launching our first piece of hardware, Home Mini, in 2022, followed by Cosy Heat Pumps in 2023 and the Charge EV Charger in 2025, we have continued to expand our portfolio of devices, helping customers make the green energy transition.

You'll join a cross-functional team of backend and mobile engineers, working closely with our hardware team to extend and improve integrations for both existing and new devices in the Octopus Energy app. This includes the recently announced Nook family of home batteries, with more exciting products already in the pipeline. If you want to design and build solutions that scale low-carbon technology in homes across the UK, this is the mission for you.

Low Carbon Tech: Low Carbon Tech are installing EV Chargers, Solar, Batteries and Heat Pumps into homes to drive the energy transition at pace. As customer demand grows, our goal is to ensure scaling up never means slowing down or compromising on a world-class customer journey for low carbon tech.

To make that happen, we are building a new, dedicated engineering and product team to completely re-imagine this process - making it fast, transparent, and predictable for our customers from day one. This will be a small multi-disciplinary team who’ll sit within our much bigger low carbon tech team.

You’ll help design and build the platform architecture, data integrations, and automations that eliminate real world friction. If you want to design and build solutions to scale up electrotech in the nation’s homes, this is the mission for you.

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

Take independent ownership of medium-sized technical features and components, delivering stable and production-ready code with minimal supervision

Ship continuously to trunk - small PRs, fast feedback, no release trains. You'll be working in a codebase with ~100 merges per week from dozens of contributors

Build and extend a Django backend serving multiple countries from a single codebase, making deliberate decisions about what should be generic vs. territory-specific

Integrate with upstream platform services (Kraken Customer, Kraken Field, Kraken Flex) that provide billing, CRM, auth, and device control - orchestrating across service boundaries daily

Proactively identify and address monitoring, alerting, and observability gaps within your applications to ensure live systems run predictably

Engage confidently in feature technical designs, participate actively in code reviews, and provide clear documentation for your pull requests

Use systematic, structured approaches to resolve bugs or service blockers, and confidently step in to address incident management within your core domain

What you'll need

Solid backend foundations with a 3-4 year track record building web applications in Python, ideally with Django. Experience writing highly testable code (unit, integration, and functional tests run in parallel in CI) and working with relational databases and background task processing

Comfortable working in a large, multi-tenant codebase - navigating and extending shared abstractions, territory-specific behaviour, and integrations with upstream services. The habit of asking "would this work for another territory?" before building something bespoke

Comfortable with pace over process - we ship continuously, not in sprints, and trust automated guardrails (type checking, linting, CI) over manual gates

Openness and excitement around integrating modern AI tools into daily development, testing, and debugging to maintain pace and spark innovation

High initiative - able to break down engineering problems into shippable slices and make steady progress when requirements are evolving or domain context is still being built

A genuine curiosity about smart energy devices and the technology that connects them to people's homes. You won't need hardware expertise, but you'll be building the software that makes these devices useful to customers

Coachable - genuinely interested in feedback and willing to adapt your approach

Our core tech stack...

Python, Django

PostgreSQL, Celery, and asynchronous background processing

API architectures: GraphQL, REST, HTTP

Domain modelling, writing fault-tolerant systems, and test-driven development (TDD)

Also valuable…

TypeScript, AWS Lambda, CDK

DynamoDB, event-driven microservices, API Gateway

Distributed architecture and scaling across services

We would prefer someone who can work in our London office but will consider remote candidates. However, you do need to be able to work 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 talent@octoenergy.com 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.