Senior Staff Full Stack Engineer - Sell Side tem

📈 Who We Are:

We are rebuilding the energy transaction, making it transparent and fair.

We're rebuilding how energy is bought and sold. That means cutting out middlemen, connecting businesses directly with renewable generators, and ensuring every transaction is traceable and transparent .

We're a 160+ person team - operators, data scientists, engineers, customer champions and energy experts - backed by top-tier investors including Lightspeed Venture Partners, Hitachi Ventures, Allianz, AlbionVC and Atomico. We closed a $75M Series B round in early 2026, taking our total funding to $94M, and we now power energy for over 4,000 UK businesses across 8,500+ sites , with over £75m in value returned to businesses and generators so far.

We're a technology company solving the energy industry, not an energy company. Some people call us a neo-utility, the neo-bank idea, applied to energy.

The industry is noticing. We were crowned Europe's Most Exciting Tech Company at the GP Bullhound Allstars awards , came in at #6 on LinkedIn's Top Startups 2026 in the UK, #7 on the Scaling Europe 50 of Europe's fastest-growing companies, and #14 on Sifted's AI 100 .

Learn more about us on our website .

🏅 The Role:

We're hiring a Senior Staff Software Engineer for Origination & New Products.

This is a hands-on technical leadership role, not a people-management one. You'll lead the Origination & New Products squad through ambiguous, no-precedent build work - deep Rosso integration, pricing capability, and deal-gating risk tooling. You won't own hiring, performance, or comp for anyone in the squad; you'll lead through technical direction, judgement, and execution.

Your squad is where you'll do the work, but it's not where your impact stops. You're accountable for outcomes that reach across the Sell team - other squads working against the same origination targets, the Engineering Manager's roadmap, and the broader engineering culture at tem. Success here looks like other squads building faster because of patterns and standards you set, not just your own squad shipping on time.

Beyond the squad, you'll be a strategic partner to the Engineering Manager, turning company-level targets into engineering outcomes - starting with growing origination volume through new products over the first 12 months, and later supporting the team as Sell Side expands internationally.

You'll lead a new three person squad to help you deliver your goals.

You will:

• Own the delivery for new product categories

• Lead technically through execution - design, build, and ship alongside the squad, not just direct it.

• Translate ambiguous, commercially-driven problems into a shape the squad can deliver against.

• Partner with commercial and product stakeholders to keep new-product work tied to real pipeline outcomes.

• Mentor the squad's engineers and raise technical standards, without owning their performance or career progression.

• Set technical direction and standards that other squads in Sell adopt - your influence is measured beyond your own team's delivery.

You will report into the Engineering Manager, Sell Side.

🚀 Responsibilities:

Lead through execution

• Drive the Origination & New Products squad's technical direction on deep integrations with other internal services

• Stay hands-on: design, build, and review the hardest parts of the new-product build sequence yourself.

• Take a company target ("grow origination volume through new products") and break it into a sequenced, deliverable plan without needing to be told how.

Build for ambiguity and risk

• Design systems for categories that don't exist yet at tem - Unlocking TWh’s of new pipeline - where the spec is being written as you go.

• Make judgement calls on commercial risk in deal-gating tooling, not just deliver what's asked.

• Prevent domain drift as new product categories are added, keeping shared language and clear boundaries.

Partner beyond the squad

• Work directly with the Engineering Manager and commercial stakeholders to keep new-product delivery tied to origination pipeline outcomes, not just shipped features.

• Be a reference point for other squads across Sell facing similar Rosso integration, pricing, or risk-tooling problems - your judgement should raise the bar beyond your own team.

• Contribute to engineering standards and practice that outlast this squad - patterns, conventions, and technical decisions other engineers in Sell (and beyond) will build on.

• As Sell Side expands internationally, represent the technical view in conversations with new-market stakeholders and partners.

• Mentor engineers in the squad and raise engineering standards, while staying on the individual-contributor track.

🎯 Requirements:

Must haves

• Proven technical leadership at Staff or Senior Staff level, with evidence of leading complex, ambiguous initiatives to real business impact - not just technical execution in isolation.

• Comfort operating without a spec: able to take a broad, undefined opportunity and shape it into something buildable.

• Sound commercial judgement - able to reason about deal risk and revenue impact, not just delivery.

• Deep enough platform fluency to integrate against a complex, business-critical system

• Track record leading a squad or team technically through direction and mentorship, without necessarily holding formal people-management responsibility.

• Evidence of influence beyond your immediate team - raising technical standards, unblocking other teams, or shaping practice that other engineers adopted.

• Strong written and verbal communication - comfortable being the technical voice in front of commercial stakeholders and, over time, external partners.

• Comfortable in our core stack: Python, AWS serverless (Lambda, API Gateway, DynamoDB, EventBridge), and event-driven architectures - the same stack Rosso and the rest of Sell Side build on.

Bonus points

• Experience in energy, fintech, or another regulated, high-stakes commercial domain.

• Experience taking a product or company into a new international market.

• 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.

✨ Benefits & Perks:

• Competitive salar y - our current band for this role is £117,850 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.

1. First call with our Talent Team (30 Mins). This is to understand your experience, motivations, and discuss the role in more detail.

2. 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.

3. Technical Interview with the Team (75 Mins) . You’ll meet with potential peers in this session and will discuss technical topics and experiences.

4. 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.