Senior Software Engineer I in Bristol

Location: London / Bristol / Edinburgh - Hybrid

Salary: £60,000 - £80,000

Reporting to: Software Engineering Manager

At this time, we are not able to offer visa sponsorship for this role. We are committed to building a diverse, global team and our sponsorship policy is evaluated on a role-by-role basis. We encourage you to keep an eye on our careers site to stay informed about future opportunities where we are able to offer visa sponsorship.

Kaluza is the Energy Intelligence Platform, turning energy complexity into seamless coordination. We help energy companies overcome today’s challenges while accelerating the shift to a clean, electrified future. Our platform orchestrates millions of real-time decisions across homes, devices, markets and grids. By combining predictive algorithms with human-centred design, Kaluza makes clean energy dependable, affordable and adaptive to everyday life.

With teams across Europe, North America, Asia and Australia, and a joint venture with Mitsubishi Corporation in Japan, we power leading companies including OVO, AGL and ENGIE, as well as innovators like Volvo and Volkswagen. At Kaluza we embrace a flexible, hybrid work model that balances autonomy with the power of in-person connection. Many of our teams find value in coming together regularly to collaborate, strengthen relationships, and accelerate progress. We’re focused on shaping thoughtful, team-driven approaches that support both business impact and individual well-being.

As we are scaling rapidly, we have a number of opportunities available across different teams and levels. The specific role you move forward with will be shaped as we progress through the interview process — allowing us to assess where your experience can have the greatest impact, with the right support around you to enable both your growth and that of the team. Our Talent Acquisition team will guide you through the details as we go.

What will I be doing?

You’ll be joining the Kaluza Technology community. We’re a large team of both data-led and product focused Software and Production Engineers, pushing the boundaries of technology and working at an extraordinary scale. As a collective we strive for engineering greatness and by ensuring best practices across the board of the community. More specifically, you’ll be working on Kaluza’s Energy Retail platform. This is a SaaS technology platform that aims to revolutionise the operating platforms for energy retailers globally. This platform has been built with scale and technical quality in mind and is the foundation for decarbonisation efforts by Kaluza’s customers.

Our tech stack is very fluid, but broadly you can find yourself working with: Typescript, Node JS, Terraform, Gitactions, Kubernetes, Docker, AWS, Kafka, GraphQL.

Responsibilities

• Design, build, and maintain scalable backend services using TypeScript.
• Work with event-driven systems and message queues to power real-time, reliable features.
• Collaborate with product managers, designers, and other engineers to build customer-focused solutions.
• Lead by example — contributing to high-quality code, mentoring others, and fostering best practices.
• Own services end-to-end, from architecture to production monitoring and continuous improvement.
• Optimise system performance and data design, working with SQL or NoSQL databases as appropriate.
• Leverage cloud platforms (especially AWS) and serverless architectures to build reliable, scalable solutions.
• Contribute to a positive engineering culture by sharing knowledge and supporting your team.

About You

• Solid experience developing backend applications, ideally in TypeScript or a willingness to pick it up quickly.
• Understanding of event-driven systems and working with queues.
• Extremely comfortable working with cloud infrastructure (AWS preferred), especially serverless technologies.
• Experience with database design, optimisation, and maintenance (SQL or NoSQL).
• Passionate about high-quality software and solving real customer problems.
• Strong communication and collaboration skills — you enjoy mentoring and knowledge sharing.
• Proactive mindset and ability to thrive in ambiguity.

Bonus

• Exposure to frontend development with React.

Why might this role not suit you?

We are going through a period of significant evolution which is exciting and with it brings lots of opportunity and challenging work, which is not for everyone. To be successful in this role, you will be excellent at operating in ambiguous, changing environments, balancing multiple priorities simultaneously and get enjoyment from making the complex, simple.

Our Software Engineering Interview Process

We aim to run a fair and transparent interview process that gives you a clear picture of the role and plenty of opportunity to show how you work.

• Initial Call with Talent Acquisition (30 minutes): A short introductory call to tell you more about Kaluza, the team, and the role, and to check that this opportunity is a good mutual fit.
• First Stage Interview (1 hour): A conversation with a hiring manager from one of our engineering teams. This interview covers both technical topics and mindset. It also includes a short 15 minute coding exercise, so please be prepared to share your screen and write some code.
• Final Interview Loop (up to 3 hours total): The final stage consists of three interviews. These are usually scheduled across multiple sessions, though we can accommodate completing them in a single day if you prefer.

Behavioural Interview: Focuses on collaboration, problem-solving, and how you deliver value for customers, using real examples from your experience.

System Design Interview: Explores how you approach complex, large-scale problems, such as designing scalable, reliable, and secure systems.

Pairing Interview: A collaborative session where you’ll work through a practical task with one of our engineers, focusing on problem-solving, clean code, and communication.

Kaluza Values

Here at Kaluza we have five core values that guide us as a business: We’re on a mission, We build together, We’re inclusive, We get it done, We communicate with purpose.

Read more about our values over on our careers site.

From us you’ll get:

• Pension Scheme
• Discretionary Bonus Scheme
• Private Medical Insurance + Virtual GP
• Life Assurance
• Access to Furthr - a Climate Action app
• Free Mortgage Advice and Eye Tests
• Perks at Work - access to thousands of retail discounts
• 5% Flex Fund to spend on the benefits you want most
• 26 days holiday
• Flexible bank holidays, giving you an additional 8 days which you can choose to take whenever you like
• Progressive leave policies with no qualifying service periods, including 26 weeks full pay if you have a new addition to your family
• Dedicated personal learning and home office budgets
• Flexible working — we trust you to work in a way that suits your lifestyle
• And more…

Even better? You’ll have access to these benefits from day 1 when you join.

We want the best people. We’re keen to meet people from all walks of life — our view is that the more inclusive we are, the better our work will be. We want to build teams which represent a variety of experiences, perspectives and skills, and we recognise talent on the basis of merit and potential. We understand some people may not apply for jobs unless they tick every box. But if you’re excited about joining us and think you have some of what we’re looking for, even if you’re not 100% sure, we’d still love to hear from you.

Find out more about working in Kaluza on our careers page and LinkedIn.