Full-Stack Engineer (Backend Focus) in London

About Volter

Volter is a top-tier climate VC-backed B2B energy tech platform building the products that make clean, renewable power simple for businesses everywhere. The energy transition is a huge and vital opportunity, but it's currently too difficult for commercial & industrial companies to achieve. Historically, the energy industry has been too opaque, complex and lacking in trust. We’re fixing that. We aim to be the “Octopus Energy for industry”: a modern tech platform providing new renewable energy products with radical transparency — accelerating deployment of renewables and helping customers cut costs and carbon without complexity. We’re excited to use technology to help our customers deploy & utilise more renewable energy and fast-forward the energy transition - and we need your help!

Role: Engineer

As a key member of the founding engineering team, you'll own end-to-end delivery of product features across the stack, building both the customer-facing interfaces and the backend services, APIs and data-powered functionality behind them. You’ll work closely with the founders, other engineers and data scientists to ship customer- and internal-facing features at high velocity—days, not weeks—while laying pragmatic, scalable foundations for our supply operations (pricing, billing, data ingestion).

You are a self-starter who excels both independently and in a team. You dislike corporate structure and bureaucracy, and believe in a "best idea wins" culture. This is why you prefer a growth-oriented, flat, startup environment. A desire to keep learning and having an impact is very important to you. You fear looking back in 10 years and realising you never made a difference…that you were simply a tiny cog in a large machine that will churn with or without you.

Day-to-day responsibilities:

• Work with commercial and product to understand customer & internal needs; shape technical solutions and roadmap
• Design, build and own features end-to-end, from backend services and APIs (i.e. billing, pricing, forecasting) through to the user-facing flows on top of them
• Build ETL pipelines to integrate with third-party systems and data sources (smart-meter/HHD feeds, market/price data, network tariff tables) with attention to data quality
• Configure, monitor and maintain appropriate logging, monitoring and observability systems
• Contribute to engineering standards: testing, CI/CD, observability, security and privacy guardrails
• Ship fast: prototype, launch, measure, and iterate with customers; maintain runbooks and documentation

What experience you bring:

We are looking for an experienced Engineer who is excited by the idea of building and owning something from the very beginning, and ideally has a strong background in backend and interest/experience in handling data.

• ~4–8 years building and operating production applications as a Full Stack engineer with strong backend skills
• Strong proficiency across the stack: backend (ideally Go and/or Python) and frontend (ideally TypeScript and React)
• Comfortable working with data-intensive features, architectures, systems and an appetite to keep improving how to scale them
• Proficient with data: schema design, query optimisation and data modelling with time-series data
• Experience designing and consuming REST APIs; event-driven patterns and background workers
• Cloud deployment with cloud providers; infrastructure-as-code (we use Terraform) and CI/CD
• Strong software engineering fundamentals: testing, code reviews, reliability/observability, performance and security-by-default

Stand-out candidates will have experience in:

• Building and owning products end-to-end in early-stage startups; balancing speed with technical debt management
• Building pipelines for external integrations and internal operations, bonus points for time-series and/or data-intensive features
• Software development in the renewables/energy space
• Collaborating with data scientists: feature serving, batch/real-time scoring, experiment tracking
• Security and compliance-aware development (least-privilege, auditability, PII handling)

Who you are:

• You are energised by early-stage businesses and thrive within startup environments.
• You are an innovative thinker who is also curious and eager to continuously learn and progress.
• You have a strong bias to action and having an impact quickly. You want to get sh*t done.
• You can take an ambiguous problem and run with it independently, while knowing when to pull others in.
• You care about customer experience as much as elegant code, and you iterate based on real feedback.
• You communicate clearly and enjoy turning messy problems into simple, robust software.
• You are a self-starter and autonomous in your way of working, but ultimately believe a team can get further together than any individual.

What you can expect from us:

• A dynamic and fast-changing environment with incredible responsibility and autonomy
• Working directly with and learning from experienced startup founders who’ve invested in and scaled businesses up to several billion dollars in valuation
• The ability to build and own something from the very beginning
• Working on market-leading and genuinely impactful products that help solve the climate crisis
• A kick-ass team of colleagues
• We value in-person time at our office in London, but offer hybrid/flexible working
• Competitive compensation based on candidate profile with generous employee equity