UI Engineer

About The Company
Yahoo Inc. is a renowned global media and technology company that connects hundreds of millions of users worldwide to the content, services, and experiences they love. With a rich history of innovation, Yahoo offers a diverse portfolio of products spanning finance, sports, news, entertainment, and advertising. The company is committed to building high-performance, accessible, and resilient digital experiences at scale, leveraging cutting-edge engineering practices. Yahoo's core focus is on developing robust platforms, collaborative tools, and design-to-code infrastructure that empower engineers and designers to create and ship intuitive user interfaces efficiently. The organization fosters a culture of excellence, innovation, and inclusivity, continuously striving to enhance its technological capabilities and user engagement.
About The Role
Yahoo is seeking a highly experienced Principal UI Engineer specializing in Design and Developer Tools to join its dynamic engineering team. This pivotal role focuses on architecting and maintaining the core platform that supports real-time collaboration, AI-augmented developer tooling, and high-performance UI components. As a Principal UI Engineer, you will lead efforts to design scalable, reliable, and efficient systems that underpin Yahoo’s collaborative editing environments and design systems. You will work at the intersection of frontend and backend development, ensuring that the platform can handle high concurrency, complex data models, and real-time synchronization with utmost reliability. Your expertise will influence the technical direction of our core infrastructure, improve developer workflows, and set standards for UI engineering excellence across the organization.
Qualifications
The ideal candidate will possess over 8 years of experience in designing, building, and operating large-scale web platforms, with substantial hands-on expertise on both frontend and backend systems. Mastery of modern TypeScript, JavaScript, React, and server-side runtimes such as Node.js or Bun is essential. Experience with real-time data models, WebSockets, and collaborative editing technologies like CRDTs (e.g., Yjs, Automerge) or Operational Transformation (OT) is required, along with a strong understanding of consistency, concurrency, and failure modes. Candidates should demonstrate solid SQL and relational database skills, particularly with PostgreSQL, including schema evolution and access control. Proven ability to diagnose and resolve complex performance issues in browsers and servers, utilizing profiling tools, heap snapshots, and tracing, is critical. Familiarity with cloud and serverless deployment, containerized services, CI/CD pipelines, and AI coding tools will be advantageous. Effective communication skills and leadership experience in driving architectural consensus are also important.
Responsibilities
As a Principal UI Engineer, your responsibilities will encompass a broad range of technical leadership and hands-on development tasks. You will own the architecture, scalability, and uptime of key infrastructure components, including real-time collaboration servers, persistence layers, background jobs, and APIs. Designing, hardening, and evolving multi-user editing systems built on CRDTs, ensuring reliable synchronization, conflict handling, undo/redo, and durable saves, will be central to your role. You will develop and maintain interfaces for AI coding agents, Model Context Protocol servers, and automated pipelines that enable safe inspection and modification of design systems and codebases. Performance profiling and optimization of rendering pipelines, hydration, bundle sizes, and server event loops will be critical to maintaining a seamless user experience. Additionally, you will oversee the evolution of our monorepo, CI/CD pipelines, automated testing frameworks, and environment management to ensure rapid, safe, and reproducible deployments.
Further responsibilities include defining observability standards through SLOs, metrics, logging, and alerting, leading incident management efforts, and implementing durable platform-level fixes. Partnering on security and access control models across systems ensures consistent enforcement of permissions. Contributions to product UI development in React and TypeScript, especially in areas demanding high performance and complex data flow, will be expected. You will also set standards for AI workflow integration, review AI-assisted code outputs for security and quality, and provide technical mentorship to senior engineers. Leading high-impact architecture reviews and aligning engineering with product and design roadmaps will be key to driving organizational success.
Benefits
Yahoo offers a comprehensive benefits package designed to support the wellbeing and growth of its employees. This includes competitive healthcare plans, a robust 401(k) retirement plan with company matching, and various wellness programs. Employees enjoy flexible hybrid work arrangements, allowing for a healthy work-life balance with occasional in-person collaboration opportunities. Additional benefits include backup childcare services, educational stipends, and access to professional development resources. Yahoo fosters an inclusive environment with employee resource groups, diversity initiatives, and programs aimed at creating a sense of belonging. The company also provides opportunities for career advancement, recognition, and participation in innovative projects that shape the future of digital experiences.
Equal Opportunity
Yahoo Inc. is an equal opportunity employer committed to fostering a diverse and inclusive workplace. All qualified applicants will receive consideration for employment without regard to age, race, gender, sexual orientation, gender identity, religion, national origin, veteran status, disability, or any other protected characteristic. The company values the unique perspectives and experiences of its employees and is dedicated to providing an accessible environment for all candidates and team members. Yahoo actively promotes policies and practices that support equity, inclusion, and respect, ensuring that everyone has the opportunity to thrive and contribute to the company's ongoing success.

Work arrangement
Yes