Principal Software Engineer

Yahoo Mail is a leading consumer inbox with hundreds of millions of users, offering a fast and organized email experience across devices. This Principal Software Engineer role is within the Yahoo Mail group, focusing on building the next generation of communication products. The team is dedicated to delivering the best consumer mail experience, meticulously refining every detail to manage the 'business of life' through email and beyond. The ideal candidate is passionate about modern technologies, cloud platforms, and creating high-quality applications, thriving on driving projects to completion and collaborating effectively with a world-class team.

Must Have

• Define, design, develop, and deliver major new features on schedule.
• Lead code reviews and contribute to technical excellence.
• Tackle complex engineering and user experience challenges.
• Take ownership of key features impacting millions of users.
• Collaborate with engineers, designers, and product managers.
• Write clean, testable, reliable code for production systems.
• Deploy, monitor, and operate globally distributed systems.
• Evaluate and recommend new technologies.
• 8+ years professional software development experience.
• Strong computer science fundamentals (data structures, algorithms, software design).
• Deep knowledge of responsive design and JavaScript frameworks (React, NextJS, Angular, Ember, Node.js).
• Advanced responsive web application development (HTML5, CSS3, TypeScript, AJAX, OO JavaScript).
• Proven understanding of software design and architecture.
• Experience with modern web technologies (Webpack, Babel, Redux Toolkit, Storybook, Atomic CSS, Superagent, Web Vitals, JSON, REST APIs).
• Hands-on experience with TDD and testing frameworks (Jest, Selenium, WebdriverIO, React Testing Library, Mock Service Worker, Playwright).
• Experience in web performance optimization, stability, and debugging.
• Excellent collaboration and communication skills.

Good to Have

• Experience developing mail applications.
• Experience with AI, ML, and GenAI.
• Experience working in Unix/Linux environments.
• Experience with mobile web development.
• Experience with Scrum, Squad, or agile methodologies.

Perks & Benefits

• Flexible-hybrid work approach
• High degree of flexibility around employee location

Yahoo Mail is the ultimate consumer inbox with hundreds of millions of users. It’s the best way to access your email and stay organized from a computer, phone or tablet. With its beautiful design and lightning fast speed, Yahoo Mail makes reading, organizing, and sending emails easier than ever.

A little about YAHOO!

Yahoo is a trusted guide for hundreds of millions of people worldwide, empowering them to achieve their goals online through a portfolio of iconic products. We connect users to what they love — from mail, finance, and sports to shopping, news, and entertainment — through trusted experiences, meaningful content, and technology that power their everyday lives.

About Our Team

Yahoo is made up of several organizations, each led by a GM and focused on driving key product lines. This role sits within the Yahoo Mail group, home to our flagship product, Yahoo Mail. You’ll be joining a team — that has a great product line, with its 4.5+ star app experiences, strong business foundation, and robust technology, is well-positioned in the consumer communication space. Now, we’re entering our next chapter: building the most consumer-focused platform for managing the “business of life,” through email and beyond. You’ll join a team of engineers dedicated to delivering the best consumer mail experience, meticulously refining every detail to make that vision a reality.

A lot about YOU

You’re passionate about growing your skills and building high-quality applications using modern technologies and cloud platforms. You thrive on creating the next generation of communication products across web or mobile. You take pride in driving projects to completion, collaborating effectively, thinking through edge cases, and understanding the broader impact of your work. You enjoy learning from experienced leaders and working with a world-class team that values clean architecture, thoughtful design, and great user experiences—while having fun along the way. If that sounds like you, we’d love to talk.

Responsibilities

• Define, design, develop, and deliver major new features for current and future products on schedule.
• Participate in and lead code reviews—learning from peers while contributing to a culture of collaboration and technical excellence.
• Tackle complex engineering and user experience challenges, delivering elegant, scalable, and user-friendly solutions.
• Take ownership of key features and product areas that directly impact millions of users.
• Partner with fellow engineers to explore creative solutions, share knowledge, and continuously improve team practices.
• Collaborate closely with designers, product managers, and cross-functional teams to deliver new features, enhancements, platform improvements, and bug fixes.
• Write clean, testable, and reliable code, deploying continuously to large-scale production systems.
• Contribute to a culture of learning through design discussions, technical reviews, and mentorship.
• Deploy, monitor, and operate globally distributed production systems with a focus on reliability and performance.
• Evaluate and recommend new technologies or approaches to solve complex problems and improve development efficiency.

Qualifications

• Bachelor’s degree in Computer Science or a related field (or equivalent experience), with 8+ years of professional software development experience.
• Strong foundation in computer science fundamentals — including data structures, algorithms, and software design principles.
• Deep technical knowledge of responsive design and javascript frameworks such as React / NextJS / Angular / Ember and Node.js
• Advanced knowledge of responsive web application development, with strong command of HTML5, CSS3, TypeScript, AJAX, and object-oriented JavaScript.
• Proven understanding of software design and architecture, including design patterns, code organization, continuous integration, and deployment practices.
• Experience with modern web technologies and tools such as Webpack, Babel, Redux Toolkit, Storybook, Atomic CSS, Superagent, Web Vitals, JSON, and REST APIs.
• Hands-on experience with test-driven development (TDD) and testing frameworks such as Jest, Selenium, WebdriverIO, React Testing Library, Mock Service Worker, or Playwright (preferred).
• Hand on experience in web performance optimization, application stability, and debugging for large-scale web applications.
• Excellent collaboration skills and the ability to work effectively with diverse, globally distributed teams.
• Strong interpersonal and communication skills; maintains professionalism, empathy, and composure in high-pressure situations.

Preferred Qualifications

• Experience developing mail application
• Experience with AI, ML and GenAI
• Experience working in Unix/Linux environments
• Experience with mobile web development
• Experience with Scrum, Squad or similar agile development methodology

Yahoo has a high degree of flexibility around employee location and hybrid working. In fact, our flexible-hybrid approach to work is one of the things our employees rave about. Most roles don’t require specific regular patterns of in-person office attendance. If you join Yahoo, you may be asked to attend (or travel to attend) on-site work sessions, team-building, or other in-person events. When these occur, you’ll be given notice to make arrangements.

If you’re curious about how this factors into this role, please discuss with the recruiter.