Principal VM Engineer – Workers Runtime Team

Cloudflare is a leading technology company focused on building a better Internet. They are seeking a Principal VM Engineer for the Workers Runtime Team to optimize and enhance the V8 virtual machine within their runtime, focusing on performance, security, and scalability in distributed environments.

Responsibilities:

• Optimize and embed the V8 VM within Cloudflare’s Workers Runtime
• Improve JavaScript execution performance and WebAssembly integration
• Debug, optimize, and enhance low-latency, real-time environments
• Ensure the reliability and efficiency of large-scale, Linux-based distributed systems
• Collaborate with engineers across runtime, security, and networking teams to push the boundaries of edge computing

Requirements:

• 6+ years of professional experience with C++
• 4+ years of hands-on VM/compiler experience, ideally with V8
• Strong knowledge of computer science fundamentals, including data structures, algorithms, and system architecture
• Experience with low-latency environments (e.g., game streaming, trading systems, high-performance computing)
• Operational mindset – you build scalable, production-ready solutions
• Deep understanding of web technologies (HTTP, JavaScript, WASM)
• Experience working with Rust in high-performance distributed systems
• Familiarity with serverless platforms and cloud computing
• Deep knowledge of JS engine internals (V8, SpiderMonkey, JavaScriptCore)
• Experience with standalone WebAssembly runtimes (Wasmtime, Wasmer, Lucet)
• Strong expertise in Linux/UNIX systems, kernels, and networking
• Contributions to large open-source projects