Senior Software Engineer, Durable Objects (DO)

Available Locations: Austin, Texas | Lisbon, Portugal | London, UK About the Department
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.
What You'll Do
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.
As a key engineer on this team, you will:

• 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++.

What We're Looking For

• 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.

Bonus Points

• 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, payment systems).
• Experience debugging, optimizing, and identifying failure modes in large-scale Linux-based distributed systems.

This is a high-impact role for engineers who thrive in fast-paced, distributed environments and want to shape the future of cloud computing. If that sounds like you, we'd love to hear from you!