Frontend Software Engineer

3+ years building production frontend applications with TypeScript and modern React.

Experience building complex user interfaces, particularly data-heavy workflows involving tables, filtering, forms, and interactive visualisations.

Understanding of frontend performance principles, including profiling, reducing unnecessary renders, and working efficiently with large datasets.

Experience working with client-side data management patterns, including caching, synchronisation, invalidation, and optimistic updates (for example, TanStack Query or similar).

Experience writing and maintaining frontend tests across different levels of the testing pyramid (for example, unit, component, integration, and end-to-end testing).

Experience building accessible, reusable UI components using modern frontend approaches such as headless component libraries and utility-first CSS frameworks (for example, ShadCN, Base UI, or Tailwind).

Ability to independently deliver well-scoped features, make appropriate technical decisions, and know when to seek input.

Comfortable collaborating closely with product, design, and engineering teams in an agile environment.

Experience working in the energy sector, or building interfaces for modelling, simulation, or scientific data.

Experience with data visualisation or grid libraries such as D3, AG Charts, or AG Grid.

Familiarity with the wider TanStack ecosystem (Router, Table, Virtual, Form).

Strong design sensibility and attention to UI/UX details.

Experience applying generative AI tools or LLMs in practical engineering workflows.

TransitionZero is a climate tech non-profit founded in 2021. TransitionZero builds software to reduce the time to build clean energy at scale. We pioneer open-access and open-source tools that make electricity system modelling more transparent, accessible, and actionable for governments, financiers and grid operators worldwide.

Our flagship tool, Scenario Builder, enables policymakers, planners and investors to rapidly build, analyse and share energy system and electricity grid models without coding expertise or external consultants. Supported by model-ready datasets, training and market insights, our tools strengthen in-house capacity and support resilient, affordable and locally-led energy transitions.