Senior Software Engineer, Durable Objects (DO)

Cloudflare • Toronto, ON

13d • Onsite

About The Position

Cloudflare’s Emerging Technologies & Incubation team builds and launches bold new products on Cloudflare’s edge network. This role is on the Durable Objects team, which powers stateful serverless applications for Cloudflare customers. You’ll help evolve the runtime and the low-level routing and storage systems that support real-time chat, multiplayer games, AI agents, and other stateful workloads at scale.

Requirements

• 5+ years of experience writing systems software.
• Operational mindset with experience owning code in production.
• Strong foundation in data structures, algorithms, and system design.
• Deep expertise in at least one systems programming language such as C/C++ or Rust.
• Experience designing and architecting large-scale distributed systems.
• Familiarity with cloud platforms, especially serverless architectures.
• Experience as a technical leader or team lead, driving engineering decisions.

Nice To Haves

• Experience working on database internals, especially SQLite.
• Deep understanding of web technologies such as browsers, HTTP, JavaScript, and WebAssembly.
• Background in low-latency, real-time environments such as game streaming, high-frequency trading, or payment systems.
• Experience debugging, optimizing, and identifying failure modes in large-scale Linux-based distributed systems.

Responsibilities

• Build and improve the Durable Objects runtime.
• Design and develop the low-level routing and storage systems that power customer applications.
• Improve reliability, scalability, performance, and feature depth.
• Own code end-to-end from design through production.
• Solve complex problems in production distributed systems.
• Work across JavaScript, TypeScript, Rust, and C++.
• Help drive the continued evolution of the system.

Benefits

• We’re not just a highly ambitious, large-scale technology company. We’re a highly ambitious, large-scale technology company with a soul.
• 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.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed