Principal VM Engineer – Workers Runtime Team

<div class="content-intro"><div><strong>About Us</strong></div> <div> <p>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. </p> <p><span style="font-weight: 400;">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! </span></p> </div></div><h3><strong>Available Locations: Aarhus, Denmark | Austin, TX | Lisbon, Portugal | London, UK | Munich, Germany</strong></h3> <h3><strong>Principal VM Engineer – Workers Runtime Team</strong></h3> <h4><strong>About the Department</strong></h4> <p>The <strong>Emerging Technologies Incubation (ETI)</strong> team at Cloudflare builds and launches bold, new products that push the boundaries of what’s possible on the internet. By leveraging Cloudflare’s massive network and edge computing capabilities, we solve complex problems at a scale few others can achieve.</p> <h4><strong>About the Team</strong></h4> <p>The <strong>Workers Runtime team</strong> is responsible for the execution environment that runs customer code at the edge. We focus on <strong>performance, security, and scalability</strong>, enhancing <strong>JavaScript APIs, WebAssembly support, and system optimizations</strong> to prepare for the next <strong>10x scale increase</strong>. Our runtime operates in a <strong>resource-constrained, highly secure environment</strong>, requiring careful management of <strong>memory, CPU, and I/O</strong>.</p> <h4><strong>What You'll Do</strong></h4> <p>We are looking for a <strong>VM Engineer</strong> to help improve and embed the <strong>V8 virtual machine</strong> in our runtime. You’ll work on <strong>low-level optimizations, performance enhancements, garbage collection, and language support</strong> to ensure our platform remains cutting-edge. This role is ideal for engineers who love tackling <strong>high-performance, low-latency challenges</strong> in distributed environments.</p> <h4><strong>Key Responsibilities</strong></h4> <ul> <li><strong>Optimize and embed the V8 VM</strong> within Cloudflare’s Workers Runtime.</li> <li>Improve <strong>JavaScript execution performance</strong> and <strong>WebAssembly integration</strong>.</li> <li>Debug, optimize, and enhance <strong>low-latency, real-time environments</strong>.</li> <li>Ensure the reliability and efficiency of <strong>large-scale, Linux-based distributed systems</strong>.</li> <li>Collaborate with engineers across <strong>runtime, security, and networking teams</strong> to push the boundaries of edge computing.</li> </ul> <h4><strong>What We're Looking For</strong></h4> <ul> <li><strong>6+ years of professional experience with C++.</strong></li> <li><strong>4+ years of hands-on VM/compiler experience</strong>, ideally with <strong>V8</strong>.</li> <li>Strong knowledge of <strong>computer science fundamentals</strong>, including <strong>data structures, algorithms, and system architecture</strong>.</li> <li>Experience with <stron ... (truncated, view full listing at source)