Head of Engineering in London

You are driven by TransitionZero's mission: building software to accelerate clean energy adoption is a matter of genuine personal urgency, not just a job. You are deeply committed to advancing the energy transition and passionate about creating high-quality software platforms. We seek individuals who exhibit ownership, accountability, and loyalty. Our culture thrives on feedback, so you must be a high-agency individual with strong self-awareness and dedicated to TransitionZero's mission.

In addition to a proactive, problem-solving mindset and keen attention to detail, as a growing organisation, we require collegiality and empathy for your coworkers. While we are a rapidly growing tech startup, we are also a non-profit, so a high level of adaptability and willingness to approach challenges with creativity and curiosity is essential.

You are:

• A hands-on engineering leader who directly manages software engineers – coaching, developing, and holding them accountable.
• A technical thinker who looks beyond the current stack to evaluate what the platform needs to truly scale, not just what is familiar.
• A delivery-focused operator who ships value incrementally and urgently, complementing visionary leadership with rigorous execution.
• A believer in engineering excellence – robust APIs, open standards, operability, and reliability as first-class concerns. You don’t accept mediocre work from yourself or others.
• Someone who understands the real-world performance and scaling challenges of running a computational platform used by external customers, and is laser-focused on user success as the driver of TransitionZero’s success.
• A confident decision-maker who can make strong calls despite incomplete or evolving information, and pivot quickly when the mission demands it.

About the role

We are looking for an experienced engineering leader to own the delivery, technical quality, and team performance of our backend platform. This platform powers Scenario Builder, our no-code electricity grid modelling interface, and is being developed as a Platform-as-a-Service (PaaS) model, enabling external users to use our infrastructure directly for energy modelling workloads.

You will directly manage the software engineering team, acting as both their line manager and delivery lead. This is not a manager-of-managers role: you will be close to the work, involved in architectural decisions, and accountable for the team’s output. You will also serve as the delivery manager for the backend platform, owning the planning, prioritisation, and execution of the engineering roadmap in partnership with Product and the CTO.

A critical part of this role is ensuring the platform is architected for the future. Our backend must evolve from serving a single product into a scalable, multi-tenant platform capable of handling computationally intensive energy modelling workloads from external users. You will need to think critically about technology choices, challenge assumptions about the current stack, and bring experience of what it takes to build and operate platforms at scale.

Responsibilities

• Platform Delivery Management

• Own the end-to-end delivery of our backend platform, ensuring commitments are well defined, prioritised, and executed on time – with a bias to action and a focus on delivering value incrementally and urgently.
• Act as the delivery manager for the platform roadmap, translating product requirements and technical strategy into actionable, sequenced engineering work.
• Ensure the team ships early and often at a high standard – prioritising actions that have the highest impact on the mission and hunting out problems before they become blockers.
• Provide clear, concise summaries of delivery status, risks, and dependencies for senior leadership.
• Partner with the Head of Product to shape roadmaps and balance feature delivery, technical debt, quality, and operational stability.
• Ensure teams use Agile practices effectively (sprint planning, stand-ups, retrospectives, estimation) and continuously improve how they work.
• Drive the transition towards a PaaS delivery model, coordinating the engineering work required to support external platform users alongside the Scenario Builder product.

• Guide the evolution of the platform architecture in collaboration with senior engineers and the CTO, with a focus on scalability, performance, and multi-tenancy.
• Critically evaluate technology choices and challenge the existing stack where necessary – advocating for the right tools and patterns to meet the platform’s scaling needs, even where that means moving beyond familiar technologies.
• Lead the design and oversight of high-performance API services that handle complex hierarchical data queries and multi-dimensional aggregations for grid modelling computations.
• Ensure the platform can handle the performance and reliability demands of running computationally intensive workloads for external users at scale.
• Champion the use of open standards (e.g. OpenAPI, AsyncAPI, CloudEvents, OpenTelemetry) to maximise interoperability and transparency.
• Ensure the team builds robust, well-crafted, documented, and versioned APIs that enable teams to interact using the Team Topologies “X-as-a-Service” model.
• Encourage innovative technical approaches that improve speed, quality, and resilience across the platform.

• Own the strategy for cloud infrastructure (GCP), ensuring it is optimised for cost, performance, and the computational demands of energy modelling workloads.
• Drive adoption of operational excellence practices: observability, monitoring, alerting, incident response, and post-incident reviews.
• Ensure observability and operability of all services, promoting a site reliability engineering (SRE) mindset.
• Promote a “you build it, you run it” culture where engineers take ownership of the services they develop, balancing delivery speed with reliability.
• Oversee CI/CD pipelines and infrastructure-as-code practices to enable rapid, reliable deployments.
• Proactively identify and address scaling bottlenecks, capacity constraints, and performance degradation before they impact users.

• Directly manage and develop a team of software engineers, providing regular 1:1s, coaching, career development support, and performance feedback.
• Build a high-performing team using DORA capabilities as a benchmark (deployment frequency, lead time, MTTR, change failure rate).
• Foster a culture of ownership, accountability, and continuous improvement – where the team actively gives and receives feedback, upskills one another, and doesn’t accept mediocre work.
• Actively remove blockers and create an environment where engineers can do their best work. Thrive under pressure yourself, but step in when someone on the team is struggling.
• Lead recruitment, onboarding, and retention of engineering talent.
• Set OKRs and support career development for direct reports.
• Promote inclusion, well-being, and psychological safety within the team.

• Collaborate effectively with cross-functional teams, including Product, Data Engineering, and Energy Modelling, to outpace the market and deliver impactful features.
• Maintain a relentless focus on user success as the driver of platform decisions – ensuring the engineering team understands how their work translates into real-world impact for energy planners and investors.
• Serve as a primary point of contact for senior leadership, providing regular updates on engineering initiatives, milestones, and performance metrics.
• Represent TransitionZero in external-facing technical contexts (e.g. technical conferences, blog posts, expert stakeholder and user discussions).
• Act as a culture-carrier for TransitionZero’s values, embodying and reinforcing the behaviours that drive the team forward - taking the mission personally, being radically self-aware, and being passionate about TransitionZero winning.

Skills and experience

• 8+ years of experience in software engineering, with a strong foundation in backend development and distributed systems.
• Proven track record as an engineering leader with direct people management responsibilities – managing engineers, not managers.
• Strong coaching and mentoring ability, with evidence of developing high-performing teams.
• Demonstrable experience building and operating scalable platforms or services – ideally with exposure to PaaS, multi-tenant architectures, or API platforms used by external customers.
• Deep understanding of performance engineering, scaling patterns, and the trade-offs involved in technology selection for compute-intensive workloads.
• Hands-on technical expertise in Python, APIs (FastAPI/Flask), containers (Docker), and CI/CD (GitHub Actions, Cloud Run/Functions).
• Strong cloud infrastructure experience (GCP preferred), with practical knowledge of cost optimisation, autoscaling, and operational monitoring.
• Experience managing delivery in Agile environments with complex data and API-driven products.
• Demonstrated ability to oversee detail and delivery while keeping sight of the bigger picture.
• Excellent communication and interpersonal skills, with the ability to influence and collaborate effectively with stakeholders at all levels.