Principal Software Engineer, Ads Platform

With Roblox’s daily active users growing at a record pace, we are seeking a Principal Engineer to join the Ads Platform team to help build the next generation of Ads infrastructure. Our team sits at the core of all advertising systems at Roblox, serving billions of ads to millions of daily users, while powering high-scale, high-throughput data systems that shape ads personalization, ranking, and measurement.

As a Principal Software Engineer on the Ads Platform team, you will be responsible for setting technical direction and leading the team in its mission to reliably serve Roblox’s massive scale. You will drive performance improvements to our ads serving and delivery infrastructure, while expanding our systems to support a variety of new and immersive ads experiences. Your scope will span across multiple teams and require close collaboration with engineers across ML, backend, and analytics to shape the future of ads infrastructure at Roblox.

This role is a great fit for you if you are proficient in managing large scale systems and data-driven applications and have a zeal for developing inspiring, easily maintainable, and reusable code. Join our highly skilled and rapidly growing team and make a significant impact at Roblox.

This position will report to our Senior Engineering Manager and require you to work onsite at our HQ in San Mateo, CA Tuesdays to Thursdays.

You Will:

• Build and ship best-in-class Ads products used by hundreds of millions of users.


• Develop backend services that scale to billions of products and transactions.


• Be a tech lead and mentor junior engineers


• Self-organize and take ownership of projects throughout their full lifecycle.

You Have

• 8+ years of experience in software development and shipping products to production


• 4+ years of server-side architecture/design at scale and compiled language experience such as C#, Java, C++, or others.


• 4+ years of experience identifying and driving solutions to difficult problems that span multiple teams and require deep technical expertise.


• Knowledge with REST, GRPC, distributed systems design, and scalable containerized systems and microservices

You Are:

• A Technical Leader: You have initiated and facilitated challenging technical solutions. Your technical expertise influences product direction. You nurture a culture of technical excellence.


• Data & System Oriented: You understand that robust data is the foundation of great ML systems, and you design infrastructure for scale, correctness, and reliability.


• Collaborative: You thrive in cross-functional teams, partnering effectively with ML, backend, and product engineers to solve complex challenges.


• Curious & Creative: You enjoy tackling hard problems, exploring new technologies, and driving continuous improvements in both systems and workflows.


• Impact Driven: You focus on outcomes - prioritizing product impact, reliability, and measurable success over code volume or complexity.