Principal UI Engineer: AI-Augmented DevTools

Yahoo Holdings Inc.; Baltimore (MD); Hybrid; USD 144,000 - 299,000; Full time

Benefits offered by this job

Flexible hybrid work

401k

Backup childcare

Education stipends

Job summary

Yahoo is seeking a seasoned Principal Engineer to own the architecture, scalability, and uptime of our real-time collaboration platform. You will lead CRDT-based multi-user editing, ensure durability across disconnects, and mentor senior engineers while collaborating with product and design teams.

You will also advance AI-enabled developer tooling, optimize performance across frontend and backend, and steer monorepo evolution, CI/CD, and testing in a hybrid Yahoo environment.

Qualifications

• 8+ years designing, building, and operating production-scale web platforms.
• Advanced mastery of TypeScript, JavaScript, React, and server-side runtimes (Node.js/Bun).
• Hands-on with real-time data models, WebSockets, and CRDTs (Yjs/Automerge) or OT.
• Strong PostgreSQL foundations; schema evolution and access-control patterns.
• Diagnostic skills for browser and server performance, profiling and tracing.
• Experience with production services: metrics, alerting, and on-call readiness.
• Cloud/serverless, containers, CI pipelines, and multiple environments.
• Daily use of AI coding agents and LLM-based tooling for code generation.

Responsibilities

• Own architecture, scalability, and uptime of the real-time collaboration server and persistence layer.
• Design, harden, and evolve multi-user editing with CRDTs to ensure durability and conflict handling.
• Architect and maintain agent-ready interfaces and Model Context Protocol servers for AI tooling.
• Profile and optimize end-to-end performance, including canvas rendering and bundle sizes.
• Lead development of monorepo tooling, CI/CD pipelines, and testing environments.
• Define SLOs, metrics, and real-time alerting; drive blameless post-incident reviews.

Skills

TypeScript

JavaScript

React

WebSockets

CRDTs

Mentoring

Tools

PostgreSQL

Redis

Playwright

Jest

Bun

Job description

Yahoo is seeking a seasoned Principal Engineer to own the architecture, scalability, and uptime of our real-time collaboration platform. You will lead CRDT-based multi-user editing, ensure durability across disconnects, and mentor senior engineers while collaborating with product and design teams.

You will also advance AI-enabled developer tooling, optimize performance across frontend and backend, and steer monorepo evolution, CI/CD, and testing in a hybrid Yahoo environment.