Senior Staff Machine Learning Engineer

Who We Are: We're rebuilding the energy transaction system, making it transparent and fair. tem exists to put power back in the hands of people. Today’s wholesale energy market is stacked in favour of the few. It's a product of an age of oil and gas, riddled with markups and middlemen. We’re changing that. Our product, RED™, built on a proprietary pricing engine that bypasses the wholesale market, enables businesses to buy the energy produced by renewable generators directly. That's 100% transparent transactions, ensuring affordable bills and fair compensation, to give every business ownership and control over where their energy comes from. Since launching in 2021, we’ve saved UK businesses and generators over £20 million, powering a growing network of forward-thinking companies, from Pizza Pilgrims to Silverstone. Backed by top-tier VCs such as Atomico and Albion, we’re creating a new category in energy - one that’s local, decentralised, and built on trust.

The Role: Do you want to work on one of the biggest problems of our time - reducing the cost of transacting electricity at scale? Energy is a first-principles input into everything: the cost of compute, the speed of AI progress, the competitiveness of nations, and even access to basic human rights. Today’s energy markets are inefficient, opaque, and expensive - and we’re building the intelligence layer that will change that. We’re looking for a Senior Staff Machine Learning Engineer to become the technical owner of Rosso, our proprietary pricing engine and core IP. Rosso is designed to solve hard, unproven problems in optimisation and risk measurement: how do we price and fulfil energy tenders across thousands of assets, in real time, while balancing portfolio risk and unlocking access to renewables at scale? This is a greenfield problem space - you’ll have the opportunity to build from first principles, shaping strategy, architecture, and modelling approach. You’ll lead the research and development of new optimisation and ML capabilities, bring state-of-the-art methods into production, and establish Rosso as the engine that powers transparent, low-cost, renewable energy markets.

Responsibilities: Own the Rosso engine: Take full technical ownership of our core pricing IP, setting the research and development strategy and ensuring continuous improvement. Build with impact: Design, implement, and deploy machine learning and optimisation models that power real-time pricing decisions at scale. Advance the science: Lead experimentation on new modelling approaches, optimisation techniques, and risk measurement frameworks to move Rosso forwards. Mentor and elevate: Provide technical mentorship to ML engineers and data scientists, raising the bar for research practices, code quality, and delivery. Shape the roadmap: Translate business needs into a clear technical roadmap for Rosso, defining success metrics and ensuring alignment with company objectives. Collaborate widely: Partner with product managers, engineers, and commercial teams to bring Rosso’s capabilities to life in market-facing products. Stay ahead: Consistently evaluate and integrate the latest advances in academia and industry to keep Rosso at the cutting edge.

Requirements: Must-Haves: Deep ML expertise: extensive professional experience in data science or ML engineering, with a proven record of taking complex models into production. End-to-end ownership: Hands-on experience designing, building, and operating large-scale cloud-based ML systems. Technical leadership: Ability to set strategy, provide mentorship, and establish best practices without direct people management responsibility. First principles thinker: Comfortable reasoning from the ground up in greenfield spaces with limited precedent. Collaborative communicator: Skilled at breaking down complex concepts for both technical and non-technical stakeholders. Product impact mindset: Proven ability to translate business needs into technical solutions that deliver measurable outcomes.

Benefits: Competitive salary - our current band for this role is £130,000 or equivalent in local currency. We review salaries twice a year using real-time market data, with transparent, consistent pay for the same role and level. Stock Options - everyone on the team has ownership in our mission. 25 days holiday + public holidays - Swap public holidays for ones that matter most to you. Plus, get an extra day off for your birthday. Remote & flexible working - We’re fully remote with clear core hours, and no internal meetings on Friday afternoons. Home working & wellbeing budgets: Up to £1,200 / €1,200 annually to upgrade your remote setup (co-working passes, equipment, etc.). Up to £150 / €150 monthly on anything that supports your wellbeing - from therapy to gym memberships to meditation apps.