Senior Frontend Developer - Build an AI Analyst in London

At Modo Energy we’re building an AI-native platform for energy markets — combining LLM agents and real-time market data to create an AI analyst that can reason about complex energy systems. Our frontend is where massive datasets, predictive models, and AI systems become usable. The stack is TypeScript, React, and Next.js in a modern monorepo architecture designed to support rapid feature development and AI-assisted engineering workflows.

We seek an experienced Front-End Engineer to lead the architectural evolution of our UI. As part of the AI team, you will design the core systems that power our platform. The AI Analyst "Ko" is an LLM-powered product embedded in the Modo Terminal that helps customers interrogate our data and research using natural language. Your main goal is to build a frontend architecture that supports rapid, AI-assisted development. You will define the design patterns, strong typing contracts and component abstractions that allow the wider engineering team to ship features quickly without compromising the architecture. By creating a robust, modular foundation you will ensure our codebase remains scalable and coherent.

Responsibilities

• Architectural Strategy: Lead the technical direction for our frontend monorepo. You will decide on state management, routing and module boundaries within Next.js and TypeScript to ensure long-term scalability and ease of maintenance.
• Component System Architecture: Design and develop our internal UI library (based on MUI). You will build reusable, strictly typed component abstractions that serve as the building blocks for the engineering team and AI agents.
• Performance Engineering: Build and improve high-performance, low-latency user interfaces. You will profile application performance, minimize re-renders and ensure the platform remains responsive under heavy data loads.
• Code Governance and Quality: Set the architectural patterns and coding standards that govern our development. You will review complex technical proposals and provide the oversight needed to ensure that high-volume contributions, including those from AI agents, adhere to robust engineering principles.
• Technical Leadership: Act as the primary expert for frontend technologies. You will guide the engineering team on UI best practices and help them use AI tools effectively while maintaining a clean and cohesive codebase.

Qualifications

• Bachelor’s/Master’s degree in Information Technology, Computer Science, or equivalent experience.
• 5+ years of professional experience in Frontend Development.
• You have a strong portfolio you are happy to share.
• You are comfortable in Figma as you are in a code editor.
• Technical / Team leadership skills.
• Strong proficiency in TypeScript, React, and modern JavaScript.
• Excellent problem-solving abilities and capacity to work autonomously and adapt to a flexible, evolving environment.
• Hands-on experience with Next.js.
• Experience with Material UI (MUI) or similar component libraries.
• Strong eye for design (UI/UX): Ability to build polished, aesthetically pleasing interfaces and bridge the gap between design and engineering.
• Solid understanding of testing principles and experience with frameworks like Jest and Cypress or Playwright.
• Proficient with Git, Docker, and CI/CD workflows.
• Familiarity with Monorepo structures and tools (e.g., Turborepo, Yarn Workspaces).
• Familiarity with Python and/or modelling is advantageous.
• Any experience of the energy sector is highly desirable.
• Any start-up / scale-up experience is beneficial.

The Company

At Modo Energy, we're on a mission to build the information architecture for the energy transition - we want to be the only place to come to for information on the global journey to net zero. We are looking for individuals who love product-building, want to work with pace at a mission-oriented startup, and will collaborate with us in shaping the culture of a rapidly growing team.

Hybrid Work Environment: This role is hybrid, with time split between working from home and our London office (Euston Square), with in-office days from Tuesday through Thursday.

Salary & Benefits

Competitive Market Rate - we want the best engineers! Equity Share Scheme. Private top-tier Healthcare and Dental coverage with Bupa, Salary sacrifice pension with 3% employer contribution; 25 days annual leave (excluding bank holidays), plus 5 flexible days to be taken on a Monday or a Friday. And lots of snacks and drinks – obviously!