Senior Software Full-Stack Engineer

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.

With 900M monthly users across Yahoo and over 200M monthly users on Yahoo Mail, Yahoo is in the middle of a true renaissance. Backed by long-term investment, modernized technology stacks, and strong leadership support, we’re operating from a position of strength—and playing offense. There’s a clear mandate to take bold bets and build user-centric experiences that redefine how people manage the “business of life.”

If you’re motivated by consumer scale, energized by big opportunities, and excited to help shape one of the largest consumer product success stories in history, this is a rare moment to join and make an outsized impact.

A Little About Us:

This role sits within the Yahoo Mail organization, home to one of the most widely used consumer products in the world. Yahoo Mail delivers 4.5+ star mobile apps and highly responsive web experiences, supported by modern front-end stacks and a backend architecture that’s actively being reimagined for the future.

Over the past year, the User Growth team has proven that delight and habit formation can drive real behavioral change at massive scale. From multi-week challenges and streak systems to smarter notification strategies and micro-delight UX, we’ve shipped programs that meaningfully increased DAU. Our experimentation velocity continues to accelerate, and each success feeds reusable lifecycle components adopted across platforms.

You’ll join a team of engineers who care deeply about craft, iteration, and outcomes—and who are excited to build 0→1 habit systems that influence how hundreds of millions of people engage with their inbox every day. Together, we’re defining the next chapter of Yahoo Mail and building the best consumer-focused platform for running the business of life, in email and beyond.

A Lot About You:

You’re energized by the opportunity to build products used by hundreds of millions of people and to directly influence user behavior at scale. You care deeply about quality, but you also know how to move fast—iterating, experimenting, and learning to drive measurable growth.

You’re comfortable operating with high autonomy, turning ambiguous problems into shipped solutions. You enjoy collaborating across product, design, and engineering to drive initiatives from idea to impact, and you’re curious about how your work fits into the larger lifecycle of user engagement and habit formation.

If you’re excited to help define how people engage with their inbox every day—and want the freedom to take big, thoughtful swings—this is the role for you.

Responsibilities:

• Build and ship high-quality, high-performance full-stack growth features for Yahoo Mail, with a strong focus on hands-on coding across React and Node.js

• Rapidly prototype, launch, and iterate on user-facing experiences using data, experimentation, and assistive AI coding to accelerate delivery.

• Collaborate closely with Product, Design, and Data partners to turn growth ideas into shipped features that drive engagement and habit formation.

• Write clean, testable, and reliable code, participating in design and code reviews while continuously deploying to production.

• Optimize application code, APIs, and user flows for performance, scalability, and reliability at consumer scale.

• Operate and improve globally distributed production systems, monitoring outcomes and iterating quickly based on real user impact.

• Grow as an engineer through regular feedback, code reviews, and design discussions in a strong culture of learning.

Qualifications:

• BS in Computer Science or equivalent practical experience, with 6+ years of professional software development.

• Strong computer science fundamentals, including data structures, algorithms, and software design.

• Proven experience building and shipping consumer-facing web applications using React (or similar frameworks) and Node.js.

• Deep understanding of modern frontend technologies, including JavaScript, TypeScript, HTML5, CSS3, and browser APIs.

• Hands-on experience designing and cons