Head of Engineering

Job title: Head of Engineering

Location: UK Hybrid (minimum working 2 days per week in our London office)

Contract Type: Permanent, Full-Time

Salary: £85,601 - £100,000

About you

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.

Scenario Builder is an in-browser platform that currently provides capacity expansion and dispatch modelling through an accessible no-code interface. The vision is to expand into power flow modelling to create a fully integrated grid modelling platform with the features and functionality needed to enable users to develop bankable scenarios that support energy investment decisions.

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.

Your key points of collaboration are with (i) the CTO to execute the technical vision, (ii) the Head of Product to align delivery with the product roadmap, and (iii) the COO to ensure engineering delivery supports business goals in a timely and cost-effective manner.

This hybrid role is based out of our London office near Waterloo Station and reports to the CTO.

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.

Technical leadership and architecture

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.

Infrastructure, scaling and operational excellence

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.

Team leadership & coaching

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.

Stakeholder and organisational alignment

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

Essential

8+ years of experience in software engin3eering, 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.

Desirable

Experience architecting platform migrations or major re-platforming initiatives (e.g. monolith to microservices, single-tenant to multi-tenant).
Familiarity with database technologies (PostgreSQL, Redis, Firestore), ORMs, and data modelling principles for complex domain models.
Experience with infrastructure-as-code tools (Terraform, Terragrunt) and GitOps practices.
Experience in the energy sector or with computational modelling/simulation software.
Familiarity with scientific computing libraries (NumPy, Pandas) and optimisation frameworks.
Experience with generative AI/LLMs in applied engineering contexts.
Exposure to geospatial data, data engineering, or analytics engineering pipelines.
Understanding of OAuth and web security best practices.
Experience designing workload-aware scaling architectures – for example, dynamically provisioning compute resources based on job characteristics such as model size, solver complexity, or simulation duration.
Familiarity with event-driven autoscaling patterns for containerised workloads (e.g. scaling compute pools in response to queue depth or job resource requirements).
Experience with incremental or delta-based data storage patterns – such as deriving new models from a base configuration and persisting only the changed values, rather than duplicating entire datasets.
Understanding of async job orchestration for long-running computational workloads, including queue management, failure handling, retry strategies, and progress reporting.
Experience designing multi-tenant resource governance – including tenant-level compute limits, fair scheduling, and noisy-neighbour mitigation.
Familiarity with platform-level result caching and memoisation strategies to avoid redundant recomputation when model inputs have not changed.

About us

We are a climate-tech startup established in 2021. We provide electricity grid modelling software to accelerate energy planning in emerging markets and developing economies. Today’s tools are costly, closed, and hard to use, with modelling studies taking months or years when they should take weeks or days. We designed Scenario Builder to meet this challenge, so energy planners and investors can make better decisions, faster.

Our funding currently comes from a range of US and EU foundations, including the Quadrature Climate Foundation, Google.org, the Sequoia Climate Foundation, Bloomberg Philanthropies, and the European Climate Foundation.

At TransitionZero, we understand that diversity is an essential component of a successful team, whether that be diverse ways of thinking, personal or professional backgrounds, or skills. We aim to be the most talented non-profit in our vertical through our culture of ownership and adaptability.

Benefits

Enhanced competitive pension scheme - auto-enrollment from day 1
25 days annual leave (excluding UK public holidays) and an additional discretionary days off such as over the festive period
20 days of annual allowance to work from anywhere in the world
Hybrid working and core working hours model
Allowance to set up your home office
Annual budget and dedicated leave time for relevant training courses
Enhanced gender-neutral parental leave (16 weeks fully paid)
Private healthcare following the successful completion of the probation period
Yearly team offsites

Our commitment to diversity, equity, and inclusion

Studies have shown that some people from marginalised or underrepresented groups are less likely to apply to a role unless they meet all of the hiring guidelines or qualifications. Whoever you are, even if you don't meet all of the criteria, if you can demonstrate a variety of skills and experience relevant to this role, we encourage you to apply as you might just be the candidate we hire! At TransitionZero, we're looking for people who are genuinely passionate about what they do, and we welcome all people, regardless of their background.

If you would like to discuss any reasonable adjustments to the application or hiring process that may better facilitate your participation, please contact our People Team (people@transitionzero.org) for an informal chat. We will make every effort to respond to your request for assistance as soon as possible.