Staff Full Stack Engineer - Buy-Side Growth

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, 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 Staff Full Stack Engineer to act as embedded technical leader for one of Buy-Side Growth's engineering squads. Buy-Side is organised into four dedicated squads, each built around a single technical leader: Self-Driving Tendering, Price Everywhere, Broker Self-Serve, and Customer Autopilot, supported by a cross-squad Architect who owns the Buy Engine and tendering service. Two of those squads - Broker Self-Serve and Customer Autopilot - don't yet have a technical leader in place, which is the clearest gap in the team today. This role exists to close that gap: to be the person a squad looks to for architecture calls, technical direction, and the judgement to pick the right bets, without needing to be a people manager to do it.

The bigger picture: Buy-Side's vision is an engine that increasingly runs itself - agents handling tendering, pricing, and customer experience end to end, so the team can serve many more brokers and customers without headcount scaling in step. You'll be building directly toward that, on a team that already ships in dedicated, focused squads rather than one team context-switching across everything.

In your first 12 months, you might:

• Step in as the embedded technical leader for a squad - most likely Broker Self-Serve or Customer Autopilot, both currently short a technical lead.
• Take Customer Autopilot from pre-discovery to a shipped first version, setting its technical direction from scratch.
• Extend the multi-broker tendering work that Self-Driving Tendering has already shipped, or push further into Price Everywhere, currently the team's biggest strategic bet.
• Mentor the engineers around you, raising the technical bar for your squad through code review, architecture proposals, and the credibility of your own delivery.
• Help design the agentic workflows that let Buy-Side handle dramatically more tenders and customers per person than it can today.

Responsibilities:

• Build with impact: Architect and deliver end-to-end systems, from internal automation to broker- and customer-facing portals, ensuring they are scalable, fast, and user-friendly.
• Lead the technical direction: Propose and own the technical direction for your squad, picking the right architectural bets and building the credibility to get others to act on your recommendations.
• Own the platform: Improve and extend core platforms and tooling, making it easier for your squad and others to build, test, and ship quality software.
• Drive innovation: Rapidly prototype and iterate on new workflows and product ideas that expand our offering and improve the broker and customer journey.
• Raise the bar: Mentor other engineers and teach your domain through code reviews and hands-on collaboration, without needing a formal management line to do it.

Requirements:

Must-Haves:

• Strong technical leadership: a track record of setting technical direction for a team or project, and getting others to commit to it through the credibility of your work, not through a management title.
• Track record in fast-paced environments: experience as a Senior or Staff Engineer in a high-growth startup or scale-up, with a strong bias toward shipping.
• System design at scale: proven ability to design and build complex systems that power both back-end automation and front-end experiences.
• Modern tech expertise: deep experience with Python (FastAPI) and modern JavaScript/TypeScript frameworks such as React.
• Product-minded mindset: experience working closely with product and design teams to solve user problems, not just deliver features.
• Can deal with ambiguity: comfortable navigating changing priorities and incomplete information to make strong technical decisions, particularly useful for a squad like Customer Autopilot that's still pre-discovery.

Desirable:

• Agentic or agent-building experience: exposure to designing multi-agent workflows or systems, which is central to Buy-Side's long-term direction.
• Exposure to the energy sector or other regulated industries.
• Experience building internal tools or platforms for brokers, sales teams, or support agents.
• Familiarity with real-time data processing systems.

Benefits & Perks:

• 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.

Interview Process: Our processes normally take around 2-3 weeks from first call to offer - please let us know about any adjustments to timelines that may be required. First call with our Talent Team (30 Mins). This is to understand your experience, motivations, and discuss the role in more detail. Behaviour Interview with our Engineering Managers (60 Mins). This is your chance to really understand the role, the expectations, and ensure alignment on ways of working. Technical Interview with the Team (75 Mins). You’ll meet with potential peers in this session and will discuss technical topics and experiences. Bar Raiser Interview with Stakeholders (45 Mins). The final session will be with two cross-functional stakeholders, and will explore how your values align with ours, and is designed to be a genuine two-way conversation, your chance to understand what it’s really like to work at tem.

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.