Senior Frontend Engineer, Annotation Tools

We're seeking a detail-oriented Senior Frontend Engineer to build world-class web-based annotation tools using React and TypeScript. You'll design and implement modular, scalable frontend architectures that power multiple annotation workflows (image, text, audio) in a shared platform.

You'll create responsive, high-quality interfaces that enable global annotators to work efficiently-combining exceptional frontend craftsmanship with thoughtful system design and AI-assisted productivity. This role is ideal for someone who values design quality, architectural clarity, and close collaboration with product and design partners.

Description

As a Senior Web Frontend Engineer, you'll lead the design and development of sophisticated React-based annotation tools that combine polished user experiences with intelligent AI integration.

You'll collaborate directly with product managers, designers, and end-users to understand annotation workflows, translate requirements into elegant web applications, and continuously improve tools that enhance annotator productivity worldwide.

You'll bring both precision and creativity-implementing pixel-accurate designs when specifications exist and exercising strong UX judgment when they don't. You'll help shape frontend systems that scale gracefully, balancing user experience, maintainability, and performance.

This role sits at the intersection of frontend engineering, design sensibility, and product thinking.","responsibilities":"Design and develop scalable, high-quality web applications using React and TypeScript for multimodal annotation workflows.

Build modular, maintainable frontend systems that enable rapid iteration and reuse across multiple tools.

Ensure responsive, accessible, and performant user experiences across browsers and devices.

Translate design specifications into precise, production-quality interfaces, while making informed, user-centered decisions when designs are incomplete.

Collaborate with product, design, and ML teams to create AI-enhanced workflows that improve annotation efficiency and accuracy.

Contribute to design systems and shared component libraries that maintain visual and functional consistency.

Partner with engineers across teams to define and uphold frontend best practices for quality, performance, and developer experience.

Preferred Qualifications

Experience designing or implementing multi-tool or modular frontend systems that support evolving product workflows.

Expertise building annotation, labeling, or complex data-visualization tools.

Experience integrating AI/ML models or SDKs into frontend applications.

Strong performance optimization skills in data-heavy, real-time, or media-rich web applications.