Staff Full Stack Engineer - DevEx

📈 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 looking for a Staff Engineer to accelerate product delivery and enable scale across our developer experience and platform engineering initiatives. You’ll contribute through hands-on coding, drive architectural direction, and raise the technical bar across the team. In your first 12 months, you’ll lead the development of systems and tooling that redefine how engineering teams build, deploy, and operate software - from internal developer platforms and CI/CD workflows to scalable infrastructure and self-serve tooling. You’ll help us improve engineering velocity, reliability, and observability while laying the groundwork for rapid, sustainable growth. 🚀 RESPONSIBILITIES: - Build with impact: Architect and deliver end-to-end systems, from internal developer tooling and platform services to scalable infrastructure components, ensuring they are reliable, performant, and easy to use. - Own the platform: Improve and extend core platforms and developer experience tooling, making it easier for teams to build, test, deploy, and operate quality software. - Drive innovation: Rapidly prototype and iterate on new workflows, automation, and platform capabilities that improve engineering productivity and operational excellence. - Partner cross-functionally: Collaborate with Product Managers, Designers, and other Engineers to scope, design, and deliver high-impact platform and infrastructure solutions. - Raise the bar: Lead by example through code reviews, mentorship, and championing engineering best practices across the team. 🎯 REQUIREMENTS: Must-Haves: - 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, platforms, and developer tooling that support engineering teams at scale. - Modern tech expertise: Deep experience with Python, Node.js, and AWS serverless architecture (e.g., Lambda, API Gateway, DynamoDB). - Front-end capabilities: Skilled in developing responsive, performant front-ends using modern JavaScript frameworks such as React. - Product-minded mindset: Experience working closely with product and engineering teams to solve developer and operational problems, not...