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Cloudflare's Emerging Technologies & Incubation team is seeking a Senior Systems Engineer to join the Workers Runtime team. This role focuses on building and improving the runtime that executes customer code at the edge of Cloudflare's global network.
You will own the full lifecycle of runtime features—from design through production—working on performance optimization, reliability improvements, and scaling challenges. Key responsibilities include building features for the Workers Runtime, improving performance and reliability at scale, expanding JavaScript API and WebAssembly support, and debugging issues in large-scale distributed systems. You'll help shape technical direction based on what's feasible and own code in production across a fast-paced, iterative environment.
Required experience includes 2+ years of professional work with C++ or Rust, strong computer science fundamentals (data structures, algorithms, software design), and an operational mindset with production system ownership. You should have deep understanding of web technologies (HTTP, JavaScript, WebAssembly) and experience debugging and optimizing large-scale Linux-based distributed systems.
Bonus qualifications include experience building high-performance distributed systems in Rust, familiarity with cloud/serverless platforms, knowledge of JavaScript engine internals (V8, SpiderMonkey, JavaScriptCore), experience with WebAssembly runtimes (Wasmtime, Wasmer, Lucet), deep Linux/UNIX/kernel/networking knowledge, and contributions to large open-source projects.
Cloudflare runs one of the world's largest networks powering millions of websites and internet properties. The company protects and accelerates internet applications without requiring hardware changes or code modifications. The culture emphasizes iteration, leveraging AI to ship faster, and ensuring improvements are shared across teams.
