Principal UI Engineer, Real-Time Collaboration & AI Tooling

Yahoo Holdings Inc. in; Reston (VA); Hybrid; USD 144,000 - 299,000; Full time

Benefits offered by this job

Flexible hybrid work options

Healthcare benefits

401k

Job summary

Yahoo Holdings Inc. is seeking a seasoned Principal Engineer to own the architecture and reliability of our real-time collaboration platform. You will lead design for CRDT-based multi-user editing, ensure data integrity across Postgres-backed persistence, and guide AI tooling integration while mentoring senior engineers.

You will optimize performance across front-end and back-end, shape scalable monorepo practices, and drive incident resilience with measurable SLOs and robust security models.

Qualifications

• 8+ years of experience designing, building, and operating production-scale web platforms, with significant time on both front-end and back-end/platform work.
• Advanced mastery of modern TypeScript, JavaScript, React, and server-side runtimes (Node.js or Bun).
• Hands-on experience with real-time data models, WebSockets, and collaborative editing (CRDTs such as Yjs or Automerge, or OT) with a solid grasp of consistency, concurrency, and failure modes.

Responsibilities

• Platform Architecture & Core Infrastructure: Own the architecture, scalability, and uptime of our real-time collaboration server, Postgres-backed persistence layer, background jobs, and the APIs that sit on top of them.
• Collaborative Systems & Data Integrity: Design, harden, and evolve multi-user editing built on CRDTs (Yjs). Guarantee reliable sync, reconnection, conflict handling, undo/redo, and save durability, so users' work is never silently lost across disconnects, deploys, or branch switches.
• AI-Augmented Developer Tooling & Agent Interfaces: Architect and maintain agent-ready interfaces, Model Context Protocol (MCP) servers, and automated pipelines that let AI coding agents and developers safely inspect, generate, and change design systems and codebases.
• Performance & Canvas Engineering: Profile and optimize end-to-end bottlenecks: interactive canvas rendering, frame rates, hydration and bundle payloads, query cost, memory footprint, and server event-loop health.
• Developer Infrastructure & Monorepo Operations: Steer the evolution of our large TypeScript monorepo, CI/CD pipelines, automated testing, and preview, staging, and production environments so shipping stays fast, reproducible, and safe.
• Observability & Systemic Resilience: Define SLOs, metrics, structured logging, and real-time alerting. Champion incident management, lead blameless post-incident reviews, and turn root causes into durable, platform-level fixes.
• Security & Access Control: Partner on authentication, authorization, and permission models across systems, branches, and files, so access rules are enforced consistently everywhere.
• UI Engineering: Contribute to product UI in React and TypeScript, especially where performance, state management, and data flow matter most.
• AI Workflow Leadership & Quality: Set standards for using AI coding agents across the software lifecycle, backed by rigorous review, static analysis, and testing that validate AI-assisted output for accuracy, security, and maintainability.
• Technical Mentorship & Governance: Set engineering standards for reliability, code hygiene, and accessibility. Mentor staff and senior engineers, lead high-impact architecture reviews, and align engineering, product, and design roadmaps.

Skills

React

TypeScript

CRDTs

PostgreSQL

WebSockets

Node.js

Performance optimization

Security & access control

Monorepo

Tools

Yjs

Redis

CI/CD

Playwright/Jest

Job description

Yahoo Holdings Inc. is seeking a seasoned Principal Engineer to own the architecture and reliability of our real-time collaboration platform. You will lead design for CRDT-based multi-user editing, ensure data integrity across Postgres-backed persistence, and guide AI tooling integration while mentoring senior engineers.

You will optimize performance across front-end and back-end, shape scalable monorepo practices, and drive incident resilience with measurable SLOs and robust security models.