Senior Frontend Engineer

About the Company

At AudienceProject, we're on a mission to bring transparency and certainty to advertising measurement. We empower brands, agencies, and publishers across the globe with tools to measure, target, and optimize their ad campaigns with unparalleled accuracy. We are a Danish-founded scale-up with an international presence, continuously pushing the boundaries of what’s possible in the adtech and martech space.

Overview

As part of our continued product expansion and platform evolution, we are looking for an experienced Senior Frontend Engineer to join our London office. This role will take ownership of critical user-facing systems within AudienceProject’s SaaS platform, ensuring they are performant, scalable, and aligned with our long-term architectural standards. You will play a key role in shaping the frontend architecture, elevating engineering standards, and delivering intuitive and high-performance experiences for our global customers. This role also carries a mentorship mandate across frontend engineering at AudienceProject. You will help define standards and best practices across multiple teams.

Key Responsibilities

• Frontend Architecture & Development - Design, develop, and maintain scalable frontend applications that power AudienceProject’s core products, ensuring high performance and reliability.
• User Experience & Product Collaboration - Work closely with Product, Design, and Data Science teams to translate business requirements into intuitive, maintainable, and technically sound frontend solutions.
• System Modernisation & Refactoring - Lead the evolution and refactoring of existing frontend systems to improve maintainability, performance, and developer experience while introducing modern best practices.
• Performance & Scalability - Optimise rendering performance, data fetching strategies, and client-side state management to support large datasets and complex analytical workflows.
• Design Systems & Reusability - Contribute to and evolve shared component libraries and design systems to ensure consistency, accessibility, and efficiency across products.
• API & Backend Collaboration - Collaborate closely with backend and data engineers to define API contracts and ensure seamless integration between frontend applications and data services.
• Quality & DevOps - Implement and maintain strong testing practices (unit, integration, and end-to-end), CI/CD workflows, and monitoring to ensure stable and secure deployments.
• Technical Leadership & Mentorship - Act as a technical mentor for frontend engineers, promoting high engineering standards, code quality, and architectural rigor.

Required Skills & Qualifications

• 5+ years of professional software engineering experience with a strong foundation in Computer Science (BSc or equivalent).
• Extensive experience building production-grade frontend applications using modern frameworks such as React, Vue, or similar (React preferred).
• Strong proficiency in TypeScript and modern JavaScript (ES6+).
• Experience designing and maintaining scalable frontend architectures in complex applications.
• Solid understanding of state management, component architecture, and performance optimisation techniques.
• Experience integrating with RESTful APIs and/or GraphQL.
• Experience implementing testing strategies (e.g., Jest, React Testing Library, Cypress or similar).
• Familiarity with CI/CD pipelines and modern development workflows.
• Excellent English communication skills.
• Strong collaboration skills and the ability to work cross-functionally.

Preferred Experience

• Experience working with data-heavy or analytics-driven applications.
• Familiarity with data visualisation libraries (e.g., D3, Recharts, ECharts or similar).
• Experience contributing to or building a design system or shared component library.
• Knowledge of frontend performance profiling and monitoring tools.
• Experience mentoring engineers or leading smaller initiatives.
• Exposure to cloud environments (e.g., AWS) and containerised deployments.

What We Offer

• The opportunity to define and take ownership of critical user-facing systems within AudienceProject’s core platform.
• A high-impact role with both strategic influence and hands-on engineering responsibilities.
• A collaborative environment that values pragmatism, autonomy, and engineering excellence.
• The chance to shape how leading global brands measure and optimise advertising effectiveness.
• A growing London presence within an international, data-driven organisation.