Senior Software Engineer, Durable Objects (DO)

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.

We realize people do not fit into neat boxes. We are looking for curious and empathetic individuals who are committed to developing themselves and learning new skills, and we are ready to help you do that. We cannot complete our mission without building a diverse and inclusive team. We hire the best people based on an evaluation of their potential and support them throughout their time at Cloudflare. Come join us!

Cloudflare's Emerging Technologies & Incubation (ETI) team is where bold, innovative products are built and launched. Rather than being limited by the structures of a large, established business, we leverage Cloudflare's global edge network to solve problems at an unparalleled scale and efficiency .

In this role, you will build Durable Objects , the Cloudflare Developer Platform's product for building stateful serverless applications . As a member of this top-notch systems engineering team, you will design and develop the low-level routing and storage systems that power Cloudflare's customers' ability to build and scale. Your job is to drive the continual evolution of the system which improves reliability, performance, and provides new features. For a recent summary of these changes take a look at this.

• Build the Durable Objects runtime which enables Cloudflare customers to build real-time chat applications, multiplayer games, and AI agents.
• Improve reliability, scalability, and performance by developing new system capabilities.
• Own your code end-to-end from design to production.
• Solve complex technical challenges with production distributed systems.
• Develop software in JavaScript, TypeScript, Rust, and C++.

• 5+ years of experience writing systems software.
• Operational mindset - we don't just write code, we own it in production .
• Strong foundation in data structures, algorithms, and system design .
• Deep expertise in at least one systems programming language (e.g., C/C++ or Rust).
• Experience designing and architecting large-scale distributed systems .
• Familiarity with cloud platforms, particularly serverless architectures .
• Experience as a technical leader or team lead , driving engineering decisions.

• Experience working on database internals (specifically SQLite).
• Deep understanding of web technologies (browsers, HTTP, JavaScript, WebAssembly).
• Background in low-latency, real-time environments (e.g., game streaming, high-frequency trading,