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Open nowPosted 42 days ago

Senior Backend Engineer

Sparta14 open roles

Where
London
Work mode
Hybrid
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Your applicationOpen nowSenior Backend EngineerSparta · London
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The clock on this job

Early applications get read.

8.0% of postings close within 7 days. Measured by our own scanner across the market. Sparta postings stay open a median of 10 days.

Share of postings closed within
  1. 1.6%1 day
  2. 3.5%3 days
  3. 8.0%7 days
  4. 14.9%14 days
  5. 34.0%30 days
This job: posted 42 days ago

Sparta median: 10 days open

The posting

We Are Sparta

Sparta is the AI leader for commodity trading, home to Leonidas AI, the first operating system for oil and commodity traders.

Backed by $42 million in Series B funding led by One Peak, with participation from returning investors FirstMark and Singular, the same investors behind AI leaders like Legora, Dataiku, and Synthesia. Most companies are building a chatbot on top of data. We've built an agent with an actual reasoning layer, grounded in years of proprietary market data and in-house trading expertise nobody else has.

We're scaling fast, and it's an exciting time to join. From independents to multinationals, the world's leading commodity teams use Sparta and Leonidas AI to move faster, trade smarter, and stay ahead of the market.

At Sparta, you'll be trusted to take ownership, backed by a team who wants you to succeed. AI is how we build here, not just what we sell. Good ideas move fast, and yours could go from staging to production in a couple of hours, whatever department you're in. You'll be challenged, supported, and given room to grow, building the AI that's changing how commodity trading gets done.

Your work has reach. From shaping Leonidas AI, to powering smarter decisions for traders around the world, to changing how commodity trading is done. And because we're growing fast, you'll accelerate your career with a level of ownership and impact you simply won't get at bigger, slower-moving companies.

At Sparta, 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.

WHY JOIN SPARTA?

At Sparta, our culture is built on innovation, collaboration, and high performance. We thrive in a fast-paced environment where initiative is celebrated, challenges are embraced, and impact is rewarded.

• Equity in a high-growth, VC-backed company

• $42M in Series B funding — strong market traction and investment

• Early-stage growth — build your career as we scale

• Market-leading product — we are redefining commodity trading intelligence

• Top-tier tools and technology to support your success

WHAT'S THE CULTURE LIKE AT SPARTA?

At Sparta, our culture isn't just a set of values on a wall — it's how we work. We embrace a dynamic environment where initiative is celebrated, challenges are met head-on, and innovation thrives. You'll collaborate with people who are passionate about our mission and committed to building outstanding products and outcomes for our customers.

THE SPARTA CODE

Understanding is non-negotiable

Understanding leads to believing. Believing leads to winning.

The 'why' is the difference between compliance and conviction. Before we execute, we ask: why does this matter, who does it serve, what changes if we win? People who understand the mission don't need to be managed.

Ask for forgiveness, not for permission

Most decisions are reversible. Most fears are not.

90% of decisions are reversible. Make them, ship, iterate. Perfection is the enemy of efficiency. Bias for action means moving before you have all the answers, but it isn't recklessness. The rule: tell the rest of us what you did, what changed, what you learned.

Fall in love with the problem

The mission wins. Your idea doesn't have to.

Solutions flatter our ego. They feel like progress. But solutions without problems are opinions, and opinions don't move customers, markets, or teammates. The goal is to find what's true, not to win the room. If your idea gets killed because a better one comes along, that's the system working.

It's your fault. Lucky you.

If it's on you, it's in your control.

True ownership sounds harsh until you feel how liberating it is. If every problem is yours, you stop spending energy on who to blame and start spending it on how to fix it. Effective leaders default to 'it's on me'. Not out of guilt, but out of agency.

Conflict is a gift

Honesty is an expression of care.

Withholding feedback is choosing comfort over growth, yours and your colleague's. Staying silent deprives others of the chance to learn. We challenge openly and with positive intent. Done with care, this builds trust. Done with ego, it destroys it.

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.

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