As a Senior Browser Extension Engineer, you'll play a key role in architecting and developing high-performance browser extensions that seamlessly integrate into our ecosystem. Tackling complex engineering challenges, influence key technical decisions, and contribute to both strategic architecture and hands-on implementation. Responsibilities ● Architect and develop robust, high-performance browser extensions using TypeScript, React, and modern frontend tooling. ● Clarify and solve ambiguous problems by identifying key requirements, breaking them down into manageable, testable components, and delivering well-engineered solutions. ● Assess and integrate third-party tools and libraries, making strategic decisions to balance trade-offs effectively. ● Drive performance optimisations by eliminating bottlenecks, enhancing UI responsiveness, reducing load times, and streamlining event handling. ● Quickly understand and debug unfamiliar code, using reverse engineering when required to analyse other extensions and diagnose issues effectively. ● Provide technical representation in cross-functional discussions, advising on feasibility, architectural considerations, and key trade-offs to guide smart product decisions. ● Build privacy-first features, prioritising secure handling, storage, and transmission of sensitive data. ● Stay vigilant to security threats, applying fundamental browser security principles to proactively mitigate risks. ● Advocate for secure coding practices, implementing safeguards to protect user data while balancing privacy, security, and user experience. ● Improve test coverage for internal npm packages, writing unit and integration tests that validate public interfaces and remain resilient to refactors. ● Drive modularity and maintainability by contributing well-documented, testable code across our libraries and browser extensions. ● Shape our automated testing strategy, exploring regression testing for browser extensions to streamline releases and catch issues early. Experience & Qualifications ● Strong commercial experience with TypeScript and React, including advanced TypeScript features and React performance optimisation. ● In-depth knowledge of front-end tooling (Redux, Webpack, Jest), leveraging these tools to maximise performance and scalability in large-scale, high-performance applications. ● Deep understanding of browser extension architecture and APIs, with hands-on experience implementing and maintaining complex features. ● Strong software engineering fundamentals, with proven expertise in event-driven and object-oriented programming and their associated design patterns to build scalable, performant, and maintainable systems. ● Strong JavaScript expertise, including asynchronous programming, event loop mechanics, closures, and functional patterns.