Principal Systems Engineer, FL Full Time NEW

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. Internet properties powered by Cloudflare all have web traffic routed through its intelligent global network, which gets smarter with every request. As a result, they see significant improvement in performance and a decrease in spam and other attacks. Cloudflare was named to Entrepreneur Magazine’s Top Company Cultures list and ranked among the World’s Most Innovative Companies by Fast Company.

At Cloudflare, we’re not looking for people who wait for a polished roadmap; we’re looking for the builders who see the cracks in the Internet that everyone else has simply learned to live with. We value candidates who have the instinct to spot a “normalized” problem and the AI-native curiosity to create a solution using the latest tools. Our culture is built on iteration, leveraging AI to ship faster today to make it better tomorrow, while ensuring that every improvement, no matter how small, is shared across the team to lift everyone up. If you’re the type of person who values curiosity over bureaucracy, and that AI is a partner in solving tough problems to keep the Internet moving forward, you’ll fit right in.

Available Locations: London or Lisbon

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. This is a unique opportunity to sit at the nexus of Cloudflare’s operations, influencing how millions of people experience the internet.

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. Join us in our mission to build a better internet for everyone!

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.

Project Galileo: Since 2014, we’ve equipped more than 2,400 journalism and civil society organizations in 111 countries with powerful tools to defend themselves against attacks that would otherwise censor their work, technology already used by Cloudflare’s enterprise customers–at no cost.

Athenian Project: In 2017, we created the Athenian Project to ensure that state and local governments have the highest level of protection and reliability for free, so that their constituents have access to election information and voter registration. Since the project, we’ve provided services to more than 425 local government election websites in 33 states.

1.1.1.1: We released 1.1.1.1 to help fix the foundation of the Internet by building a faster, more secure and privacy-centric public DNS resolver. This is available publicly for everyone to use – it is the first consumer-focused service Cloudflare has ever released. Here’s the deal – we don’t store client IP addresses never, ever. We will continue to abide by our privacy commitment and ensure that no user data is sold to advertisers or used to target consumers.

Sound like something you’d like to be a part of? We’d love to hear from you!

This position may require access to information protected under U.S. export control laws, including the U.S. Export Administration Regulations. Please note that any offer of employment may be conditioned on your authorization to receive software or technology controlled under these U.S. export laws without sponsorship for an export license.

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, or any other person’s, perceived or actual 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. We are an AA/Veterans/Disabled Employer.

Cloudflare provides reasonable accommodations to qualified individuals with disabilities. Please tell us if you require a reasonable accommodation to apply for a job. Examples of reasonable accommodations include, but are not limited to, changing the application process, providing documents in an alternate format, using a sign language interpreter, or using specialized equipment. If you require a reasonable accommodation to apply for a job, please contact us via e-mail at hr@cloudflare.com or via mail at 101 Townsend St. San Francisco, CA 94107.