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Octopus Energy

Senior Backend Engineer - Python

Become a Senior Backend Engineer with Octopus Energy in Tokyo, Japan. Lead backend development for innovative energy products, focusing on scalable services. Enjoy a dynamic work environment and the chance to make a real impact on the renewable energy transition.
Octopus Energy
Octopus Energy
Tokyo, Japan   Hybrid   Full Time  UTC+09:00

Octopus Energy

Company Overview

Octopus Energy, a subsidiary of Octopus Capital Limited, part of the Octopus Group

London, United Kingdom

2015

Approximately 3,000 employees globally (source: linkedin.com). No public revenue figures for 2023 or later are disclosed, but it manages £7 billion in renewable assets and £6 billion in generation capacity powering four million homes (source: octopusenergy.com).

What They Do

Octopus Energy has rapidly evolved from a UK energy supplier into a global entity, offering a diverse range of services and products. The company focuses on technology-driven energy solutions, primarily through its Kraken Technologies platform, which utilizes machine learning for customer-centric automation and supply chain management. This platform is licensed to utilities such as EDF Energy and E.ON, supporting over 50 million accounts worldwide (source: octopusenergy.group). Their offerings include 100% renewable electricity tariffs, time-of-use plans, and EV concierge services, catering to residential households, businesses, and global utilities (source: octopusenergy.com). With a strong emphasis on integrating renewable energy sources, Octopus Energy targets customers who are EV owners, solar adopters, and smart home users, providing them with innovative solutions that promote savings through dynamic pricing (source: energydigital.com).

Projects & Track Record

Octopus Energy Generation manages a portfolio of 300 projects across eight countries, primarily focusing on solar and offshore wind energy. With £6 billion in assets, these projects power approximately four million homes, and the company has established a reputation for paying 100,000 UK households for solar exports, generating 1.2 billion kWh annually (source: octopusenergy.com). Notable projects include the acquisition of Zestec Renewable Energy in December 2022, which aimed to expand their renewable energy capabilities, and a carbon-neutral bid deal in Manchester targeting 2038 neutrality (source: wikipedia.org). The company is also actively involved in ongoing initiatives like KrakenFlex, which balances grid energy through the integration of EVs, batteries, and solar technology (source: octopusenergygeneration.com).

Recent Developments

In recent years, Octopus Energy has made significant strides in expanding its market presence. In September 2023, the company completed the acquisition of Shell Energy's UK and German household businesses, which increased its domestic and business customer base to 6.5 million, achieving a 22% market share in the UK by April 2024 (source: wikipedia.org). Additionally, the company announced plans to spin off Kraken Technologies in September 2025, a move aimed at scaling operations to over seven million UK customers and enhancing its energy transition technology (source: youtube.com). These developments underscore Octopus Energy's commitment to innovation and growth in the energy sector.

Working There

Octopus Energy offers a variety of roles across multiple departments, including retail supply, technology development, and renewable energy project management. The company actively hires at its London headquarters, as well as in Manchester, Newcastle, Rotherham, and Birmingham, with employee ratings on platforms like Indeed reflecting a positive workplace culture (3.9/5 in London, 4.2/5 in Manchester, and 5.0/5 in Rotherham) (source: indeed.com). The culture at Octopus Energy emphasizes customer centricity and long-term investment in both people and technology, fostering an environment where employees are encouraged to innovate and contribute to the company's mission of providing sustainable energy solutions (source: energydigital.com). While specific benefits such as salaries or health plans are not publicly detailed, the company is known for its commitment to low-cost service and scalable tech career growth opportunities across its international operations.

Contact


Last updated on 2026-01-02 | Report an issue

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 earlier this year, we became Britain's largest energy supplier.

In 2021, we brought this mission to Japan – the world’s largest liberalised energy market. Here, we are committed to making energy better for both customers and the planet, while driving the growth of green energy across the country. In our lean and fast-moving team in Japan, every idea and action has the power to create a real impact on both business and society.

We're scaling fast and building the next generation of products to accelerate the green energy transition. From making it effortless to switch to heat pumps, solar and EVs, to launching smart tariffs and creating renewable generation at scale, we're solving some of the most complex challenges in energy with speed, creativity and customer obsession. Here in Japan we’re following in the footsteps of the UK, taking their learnings, and adopting products and experiences that customers love.

As a member of the Octopus Tech Team, you'll have real ownership, variety, and the chance to shape products that make a tangible difference in people's lives – lowering bills, enabling greener living, and delivering experiences customers genuinely love. You'll work side by side with teams across customer service, sales & marketing, operations, finance and data, and see the impact of your work in the real world, fast.

We’re looking for people who want to take part in this journey and help shape the future of energy in Japan. If this sounds exciting, we'd love to chat.

There’s a couple of things you should be aware of about this role. You will initially be employed by Kraken Tech Japan, our sister company in Japan, then, at some future time, transfer your employment to Octopus along with other tech staff in our other markets across the world.

We’re expanding the scope of our tech team, and we are looking for a Backend Engineer to join our team to lead backend development on some exciting new products. You will play a key role in leading the backend domain and building scalable, reliable services that power the future of energy in Japan.

What you’ll do…

  • Develop and operate Octopus Energy’s core global backend system
  • Build and operate Octopus Energy products for the Japanese market (with many on the horizon)
  • Design and develop APIs to integrate with other systems and services
  • Collaborate with international teams (UK, EU, APAC and USA) in global development projects

What you’ll need…

  • 3+ years of professional experience in backend web application development
  • Hands-on experience with Python/Django or equivalent web frameworks
  • Experience designing and operating RDBMS (e.g., PostgreSQL, MySQL)
  • Experience in team development using Git
  • Experience with large-scale or high-transaction systems
  • Experience developing and operating systems in cloud environments (AWS, GCP, or Azure)
  • Experience with microservice architecture
  • Ability to communicate in English (participating in meetings and discussions, reading and writing)
  • Interest in environmental issues and the energy industry

What We’re Looking For…

  • A self-sufficient person with a high level of initiative and who enjoys working in a fast-changing environment and can work autonomously
  • A strong team player who collaborates across teams and departments
  • Someone excited to solve social challenges through technology
  • Ability to communicate in English is essential

We're looking for someone with a general interest in technology and problem-solving; someone diligent and thoughtful. It would be helpful to have experience/expertise in the following (in rough priority order):

  • Python
  • Django (or equiv. web framework)
  • Domain modelling
  • HTTP and REST APIs, GraphQL and other API technologies
  • Writing robust and fault-tolerant software
  • Celery and async processing
  • Postgres

Plus experience in the following would be a bonus:

  • AWS
  • Terraform, Packer, Consul
  • Ability to speak Japanese would be a plus

We would prefer someone who can work in our Tokyo office but will consider remote candidates. However, you do need to be able to work in Japan.

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 [email protected] and we’d love to help!

If this sounds like you then we'd love to hear from you. 🚀

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.

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About the role

September 20, 2025

Full Time

Company

January 9, 2026

Hybrid

Octopus Energy

octopus.energy

  •  Tokyo, Japan

3+ years of professional experience

UTC+09:00

Apply now

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