Principal Systems Engineer, FL in London

Join to apply for the Principal Systems Engineer, FL role at Cloudflare. At Cloudflare, we are on a mission to help build a better Internet. Today the company runs one of the world's largest networks that powers millions of websites and other Internet properties for customers ranging from individual bloggers to SMBs to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code.

The Team: Cloudflare's Front Line (FL) group operates the world's largest web server, which processes over 120 million HTTP requests every second. We are the guardians of Cloudflare's core infrastructure. As part of the Platform team, you will play a pivotal role in evolving this system. We are a team of senior engineers and architects building and maintaining a web proxy platform that is not just performant but also offers exceptional developer ergonomics for over 20 other teams. Our entire codebase is written in Rust.

The Role: As a Senior Engineer/Architect on the Platform team, you will be instrumental in building the next generation of our core web server. This is more than just maintaining a system; it's about innovating and building a platform that empowers teams across the company. You will coordinate efforts across multiple teams to design, build, and deploy new features that enhance the availability, safety, and reliability of our edge network. Your primary focus will be on building a high-performance platform with a keen eye on operational excellence. This includes defining and implementing clear Service Level Objectives (SLOs), monitoring key metrics, and managing error rates to ensure a robust and reliable system.

What You'll Bring: We are looking for seasoned professionals with a strong background in software architecture and distributed systems. Deep expertise in Rust, with a history of building complex, production-grade applications. Strong competencies in computer science, including a solid understanding of algorithms, data structures, and concurrency control. Experience with performance engineering and a proven track record of optimizing high-throughput, low-latency systems. Excellent communication and collaboration skills to drive consensus and coordinate with diverse engineering teams. A passion for continuous improvement in both operations and product development.

Bonus Points: A deep understanding of web protocols and web servers. Experience with distributed systems architecture. Knowledge of web security issues and industry standards. Familiarity with Prometheus for monitoring and alerting. Most importantly, we're seeking a builder—someone who is excited by the challenge of working on a system at a scale few companies ever reach.

What Makes Cloudflare Special? We're not just a highly ambitious, large-scale technology company. We're a highly ambitious, large-scale technology company with a soul. Fundamental to our mission to help build a better Internet is protecting the free and open Internet.

Cloudflare is proud to be an equal opportunity employer. We are committed to providing equal employment opportunity for all people and place great value in both diversity and inclusiveness. All qualified applicants will be considered for employment without regard to their race, color, religion, sex, gender, gender identity, gender expression, sexual orientation, national origin, ancestry, citizenship, age, physical or mental disability, medical condition, family care status, or any other basis protected by law.