Principal Frontend Web Engineer

We are seeking a Principal Software Web Engineer who will lead the next generation of communication products on the web and set the technical direction for how our team builds in an AI-First world. As a Principal, you will operate as both an architect and a validator of high-quality code. You will orchestrate AI-assisted workflows to accelerate delivery while maintaining the architectural judgment, security posture, and user experience that millions of users rely on. You have a deep commitment to modern web stacks, cloud-scale systems, and pushing the team toward structured, AI-augmented engineering practices. You enjoy mentoring engineers, exploring new technology, and turning rough ideas into elegant, production-grade products. If you care about code quality, architecture, design, and user experience and treat AI as a force multiplier rather than a replacement for engineering rigor, we want to talk to you., * Feature Leadership & Delivery: Define, design, develop, and ship major new features in current and future web products, owning them end-to-end from requirements through production monitoring.

• AI-First Workflow Orchestration: Leverage approved AI-assisted tools (such as Cursor and Claude Code) to accelerate implementation while maintaining architectural integrity, code quality, and security.
• Lifecycle Optimization: Identify and implement AI-driven efficiencies across the development lifecycle, replacing manual boilerplate and repetitive refactors with automated, AI-validated workflows.
• Technical Judgment & Oversight: Balance AI-generated outputs with manual oversight, reviewing generated code for architectural correctness, performance, and adherence to strict accessibility and security standards.
• High-Scale Impact: Take ownership of web application areas impacting millions, tackling hard engineering and UX problems with elegant, seamless solutions.
• Quality & Collaboration: Perform thorough code reviews and collaborate with UX designers and product managers to deliver platform improvements and critical bug fixes.
• Operational Excellence: Write testable, reliable code and deploy, monitor, and operate large-scale production web systems distributed across the globe.
• Mentorship & Innovation: Mentor engineers across the squad and adjacent teams to scale AI-first best practices, establishing guardrails for AI-augmented coding, and evaluating emerging tooling to keep Yahoo at the leading edge.

• BS in Computer Science (or equivalent years of experience) with 8+ years of professional software engineering experience (or equivalent years of experience)
• Strong understanding of the fundamentals including Data Structures, Algorithms, and Software Design
• Deep technical knowledge of responsive design and modern JavaScript frameworks (e.g., React, Angular) and Node.js
• Expertise in web application development with a strong command of browser-side technologies including HTML5, CSS3, TypeScript, and OOP JavaScript
• Proven expertise in software development principles, including design patterns, CI/CD, and deployment architecture
• Experience with modern web technologies like Webpack, Redux Toolkit, Atomic CSS, Storybook, and REST APIs
• Expertise in test-driven development and frameworks such as Jest, Selenium, Playwright, and React Testing Library
• Expert knowledge of web application performance, stability, and debugging
• Hands-on experience with approved AI code-assist tools (such as Cursor and Claude Code) integrated into daily development workflows.
• Proficient in writing clear prompts, engineering context-rich system prompts, and iterating on AI suggestions to achieve robust implementation results.
• Commitment to evaluating and validating AI-generated outputs to detect logical errors, security vulnerabilities, and code regressions.

Preferred Qualifications:

• Experience developing Mail or Calendar applications
• Experience with ML and GenAI, including building user-facing features powered by LLMs.
• Experience working in Unix/Linux environments
• Experience with mobile web development
• Experience with Scrum, Squad, or similar agile development methodologies
• Exposure to accessibility (a11y) or internationalization (i18n) for large-scale systems

The material job duties and responsibilities of this role include those listed above as well as adhering to Yahoo policies; exercising sound judgment; working effectively, safely and inclusively with others; exhibiting trustworthiness and meeting expectations; and safeguarding business operations and brand integrity.

The compensation for this position ranges from $143,625.00 - $299,375.00/yr and will vary depending on factors such as your location, skills and experience.The compensation package may also include incentive compensation opportunities in the form of discretionary annual bonus or commissions. Our comprehensive benefits include healthcare, a great 401k, backup childcare, education stipends and much (much) more.

The client experiences team develops products for Yahoo Mail on Android, iOS, and Web used by over 220 million users across 40 countries and 70 languages. Yahoo Mail continues to be one of the largest and most recognizable email services in the world. Delivering over 4.5B emails daily, and with consistently top-rated mobile apps, Yahoo Mail is a critical pillar in the company’s long-term growth strategy. You will join a team of engineers who strive to deliver our users the best consumer mail experience and are willing to meticulously refine the details to achieve this goal.