Software Engineer, Rulesets

About Us

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 (Hybrid)

About Engineering at Cloudflare

Cloudflare’s Engineering team is responsible for the software platform that serves 115 million HTTP requests per second on average. We also build and run the tools that empower our colleagues to rapidly deliver products to market, as well as monitor and deploy software updates across the globe to 350+ data centers. You’ll experience the full breadth of technologies needed to run one of the world’s largest networks serving the world's largest customers such as Shopify and VISA.

About The Team

Cloudflare’s Front Line (FL) group is responsible for maintaining and developing the main Cloudflare web server, processing over 100 million HTTP requests per second. In other words, we own the largest web server in the world.

The Product Team is responsible for creating new customer-facing features, improving efficiency & safety, and building the next iteration of Cloudflare products. The platform is mostly in Rust, and most of our API is in Golang.

What you'll do

You will work with a team of talented engineers to create new features to increase the availability, safety & reliability of the edge ecosystem. You will improve current features, create new systems from scratch, and collaborate with platform teams to help to build the best web server in the world, with a particular focus on the rules engine and associated control plane.

This is a unique opportunity to be at the nexus of Cloudflare edge applications and operations and to collaborate closely with most other product and engineering teams at Cloudflare.

Examples of desirable skills, knowledge and experience

Solid competencies in practical computer science, applying the right algorithms, data structures, concurrency control systems to software design, and building large, distributed systems

Experience in performance engineering

Driving communication and consensus across teams

A drive for continuous improvement when it comes to both operations and new product development

Bonus Points

These are things which the role is likely to require; we’re happy to help you learn on the job, but prior experience is beneficial

Experience of languages: Rust, Go

Knowledge of web servers and web protocols

Distributed systems

Web security issues and industry standards

Most importantly, we are looking for people who want to learn something new. We maintain the largest web server in the world, and we