Senior Staff Engineer - Payments

📈 Who We Are: We are rebuilding the energy transaction, making it transparent and fair. Our goal is to put power back where it belongs, in the hands of customers and to take on one of the most critical problems of our century, access to low cost electricity. tem exists to fix a broken global energy market that’s long favoured legacy operators, intermediaries, and opaque pricing. Today’s electricity system was not designed for rapid decarbonisation, AI-driven efficiency or fair access for the actual users - businesses and generators. We’ve built the first AI native transaction infrastructure to reinvent how electricity is bought, sold and priced. Our technology is designed to cut out the inefficient fees, automate complex market flows, and bring transparency and fairness to energy transactions at scale. In late 2025, after extraordinary growth, we closed a $75 million Series B - led by Lightspeed Venture Partners with participation from Albion, Atomico, Allianz, Hitachi Ventures, Hitachi Ventures, Schroders Capital and others - positioning us for global expansion, deeper product innovation and category leadership. We’re scaling internationally and building toward a future where AI-driven infrastructure is foundational to electricity markets worldwide. Since launch, our modern utility product, known as RED, has already facilitated thousands of business customers and billions in energy transaction value, proving that modern software and AI can transform an industry built on legacy systems. At tem, we’re not just building another energy company, we’re rearchitecting market infrastructure so that transparency, efficiency and sustainability become the default, not the exception. 🎯 THE ROLE We're hiring a Senior Staff Engineer for our brand new Payments squad, part of Saldo, our Billing and Payments Service. Payments at tem works today, but it's a basic service. We're growing fast, and it needs to be built for the scale we're moving towards. You'll be the first tech lead in a squad that already has a senior engineer and three junior engineers, and you'll own the outcome of the squad's delivery and the standards it works to. This is a hands-on role. You'll write design docs, review code, solve the hardest problems alongside the team, and set the technical direction for payments. The number you'll move is the cost of processing every pound that flows through tem. Your job is to bring it down, and keep it low as we scale. In your first 12 months, you might: - Set the architecture direction that takes payments from a functional service to one built for growth. - Define how the squad works, including the balance between speed, quality and resilience that payments demands. - Lift the quality and speed bar for the whole squad, senior and junior engineers alike. - Drive the technical blockers to delivery to resolution, so the squad's work reaches the people who depend on it. - Make payment accuracy and processing efficiency the levers that bring cost-to-process down. You'll report into the Service Manager for Saldo. 🛠️ RESPONSIBILITIES - Own the outcome: Take responsibility for the squad's delivery and the standards it works to, so the team ships work we're proud of. - Lead from the front line: Write specs and design docs, give feedback on ADRs, review pull requests, and solve problems directly through code or workflows. - Set the payments architecture direction: Turn a genuinely ambiguous area into a clear technical strategy, without waiting for someone else to define the problem. - Cut the cost to process: Own payment accuracy and processing efficiency as the direct levers on cost-to-process. - Design how the squad works: Define the squad's operating model and set the pace, rather than waiting for a playbook. - Own the big picture: Manage sequencing and dependencies, diagnose why throughput isn't improving, and make sure the squad's work is visible to stakeholders. - Build a high-performance team: Coach junior engineers while working the hardest problems alongside our senior engineer, and define what good looks like by working the details with the team. - Partner on people decisions: Flag promotion and hiring gaps to your manager, who keeps line management and performance conversations. Decisions on people are made jointly. ✅ REQUIREMENTS MUST-HAVES - A track record as a tech lead, owning the outcome of a squad's delivery and the standards it works to. - A track record of leading from the front line: writing design docs, reviewing PRs and ADRs, and solving problems hands-on while setting direction. - The ability to balance hands-on work on the biggest technical challenges with coaching more junior engineers, holding the whole team to a consistent quality and speed bar. - Experience designing a team's ways of working from scratch, balancing speed, quality and resilience. - Experience owning cross-team sequencing and dependencies, and diagnosing throughput problems rather than just reporting them. - Comfort cutting through real ambiguity to set technical direction, and driving technical blockers to resolution rather than just visibility. DESIRABLE - Experience with payments systems. - Experience improving cost-to-process or processing efficiency in a high-volume service. - Experience taking a service from a basic first version to something built for scale. 🎁 BENEFITS & PERKS - Competitive salary. - Stock options so everyone has ownership in our mission. - 25 days holiday plus public holidays. Swap public holidays for the ones that matter most to you, and enjoy your birthday off. - Remote first and flexible working, with clear core hours and no internal meetings on Friday afternoons. - Up to GBP1,200 or EUR1,200 per year for your remote setup. - Up to GBP150 or EUR150 per month for wellbeing. 🤝 INTERVIEW PROCESS - First call with our Talent Team (30 mins). - Behaviour Interview with the Hiring Manager (60 mins). - Technical Interview with Martin and/or Pawel (90 mins). You will discuss system design and have a technical Q&A. - Culture-Add Interview with Product and Leadership stakeholders (45 mins). We welcome applications from people of all backgrounds, experiences, and identities, including those that are traditionally underrepresented in the tech and energy sectors. If you’re excited about this role but not sure you meet every requirement, we’d still love to hear from you. Your unique perspective could be exactly what we’re looking for.