Backend Engineer (Mid/Senior) in London

Sparta is the next-generation commodity trading platform. We give trading desks the clarity, control, and collaboration they need to move faster and trade smarter. In February 2025, we secured $42 million in Series B funding. Now we’re scaling up across the business, and it’s an exciting time to join.

Our people are the driving force behind everything we do. At Sparta, you’ll be trusted to take ownership, backed by a team who wants you to succeed. You’ll be challenged, supported, and given room to grow. Because building something this ambitious takes everyone at their best.

At Sparta, your work has reach. From improving our platform, to powering smarter decisions for our customers, to changing how commodity trading is done around the world. And because we’re growing fast, you won’t just build your career. You’ll accelerate it, with a level of ownership and impact you simply don’t get at bigger, more bureaucratic companies.

We’re on a mission to build the next generation of commodity trading platforms - replacing the fragmented tools that traders typically rely on with a single, powerful dashboard. Our product is a data-driven platform that aggregates real-time feeds from across the commodities domain, transforming them into intuitive, actionable visualisations within one unified interface. Users can explore pre-built data views or define their own custom formulas to create tailored insights.

To deliver on this vision, our engineers tackle real distributed systems problems on a daily basis, where designing for reliability and performance at scale is essential to a seamless user experience. As we unlock the next level of scale, those problems get harder and more interesting. This role is for an engineer who wants to own meaningful parts of that system now, and grow into the technical decisions that shape it.

We’re looking for people who thrive in an empowered environment - engineers who are comfortable being given problems to solve rather than solutions to implement. You should enjoy working at pace, value autonomy, and prefer to ask for forgiveness rather than permission. You won’t be handed tickets. You’ll be handed context, and trusted to work out the right thing to build.

Whereas Sparta is a remote-first company, for this role we’re looking for someone who values a hybrid working style, which in a typical week could involve spending a couple of days in the office - with flexibility built in.

WHAT YOU’LL BE DOING:

• Design, build and maintain the backend services behind our real-time and analytical data processing.
• Own features end to end, from shaping the approach to running them in production.
• Optimise pipelines and services for low latency, high throughput and scale.
• Work with engineers, product and stakeholders to stay aligned on direction.
• Contribute to design reviews with a clear view on the trade-offs.
• Keep your services healthy - observability, feedback loops, incident response.
• Raise the bar around you through code review, pairing and knowledge sharing.

ABOUT YOU:

• 4+ years as a software engineer, with production systems you’ve built and supported.
• High ownership tendencies.
• Experience in a product-focused organisation, working cross-functionally.
• Comfortable across multiple languages. We mainly use Kotlin, Java, Python and TypeScript.
• Able to reason about trade-offs - throughput, latency, consistency, cost - and explain them.
• At home in system design and in low-level implementation detail.
• Experience building and deploying services on AWS or GCP.
• Hands-on exposure to Kafka, Flink, Redis or clustered Postgres, and an appetite for more.
• Comfortable with agent-based development tools. We use Claude Code; any equivalent is fine.
• A clear communicator and a pragmatic problem-solver.

NICE TO HAVE EXPERIENCE:

• Data-intensive applications at scale.
• Building and interpreting observability - metrics, logging, tracing.
• Working within or alongside DevOps, SRE or infrastructure teams.
• Complex distributed environments - high throughput, low latency, large datasets.
• Any exposure to commodities, energy or financial markets. Useful, but we’ll teach you the domain.

Sparta Commodities is proud to be an equal opportunity employer and promotes diversity within its workforce. We are determined that no-one will ever receive less favourable treatment on the grounds of gender, age, disability, religion, belief, sexual orientation, marital status, race, veteran status or any basis covered by appropriate law.