Staff Full Stack Engineer - Sell Side Engine

tem is rebuilding energy transaction infrastructure with AI-native technology. They are hiring a Staff Full Stack Engineer for the Sell Side Engine to work on integration-heavy systems using Python, AWS serverless, and React/TypeScript.

• Go deep on hard systems: Own architecture-level decisions on integration-heavy systems, reasoning clearly about boundaries, contracts, and failure modes.
• Build for ambiguity: Take a piece of an undefined, commercially-driven problem and turn it into a shippable plan, within the direction your squad lead sets.
• Work across boundaries: Deliver on dependencies that sit with teams you have no authority over, such as Rosso, Data, and Billing, getting integrations right without needing to own the relationship.
• Build with impact: Design, build, and ship the hardest parts of the new-product build sequence yourself, backend-first but comfortable moving into the React/TypeScript front end when it matters.
• Maintain high standards: Write clean, well-tested code, contribute to code reviews, and help improve team practices and documentation.

• Deep technical depth in backend and systems design, with a track record of owning architecture-level decisions on complex, integration-heavy systems.
• Comfortable in our core stack: Python, AWS serverless (Lambda, API Gateway, DynamoDB, EventBridge), and event-driven architectures. React/TypeScript exposure is a plus but not the bar.
• Comfort operating without a full spec: able to take a defined slice of an ambiguous problem and turn it into a shippable plan.
• Experience delivering work where a critical dependency sits with a team you have no authority over.
• Proven product delivery experience: experience as a Full Stack or Backend Engineer in a startup or fast-paced product environment, with ownership of complex projects from start to finish.
• Prior experience mentoring engineers or setting technical direction, even without a formal leadership title. Not required. We'd rather have a brilliant engineer who has never led a squad than a mediocre one who has.
• Experience in energy, fintech, or another regulated, high-stakes commercial domain.
• Exposure to workflow orchestration, event-driven systems, or real-time pricing engines.
• Experience originating new product lines from scratch rather than only scaling existing ones.

• Competitive salary - our current band for this role is £104,000 or equivalent in local currency.
• We pay against a clear benchmark for your role and level. No fixed once- or twice-a-year cycle - pay moves when the evidence for it does.
• 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.