Principal VM Engineer Workers Runtime Team

Available Locations: Aarhus Denmark Austin TX Lisbon Portugal London UK Munich Germany

Principal VM Engineer Workers Runtime Team

About the Department

The Emerging Technologies & Incubation (ETI) team at Cloudflare builds and launches bold new products that push the boundaries of whats possible on the internet. By leveraging Cloudflares massive network and edge computing capabilities we solve complex problems at a scale few others can achieve.

About the Team

The Workers Runtime team is responsible for the environment that runs customer code at the edge. We focus on performance security and scalability enhancing JavaScript APIs WebAssembly support and system optimizations to prepare for the next 10x scale increase. Our runtime operates in a resourceconstrained highly secure environment requiring careful management of memory CPU and I/O.

What Youll Do

We are looking for a VM Engineer to help improve and embed the V8 virtual machine in our runtime. Youll work on lowlevel optimizations performance enhancements garbage collection and language support to ensure our platform remains cuttingedge. This role is ideal for engineers who love tackling highperformance lowlatency challenges in distributed environments.

Key Responsibilities

• Optimize and embed the V8 VM within Cloudflares Workers Runtime.
• Improve JavaScript performance and WebAssembly integration.
• Debug optimize and enhance lowlatency realtime environments.
• Ensure the reliability and efficiency of largescale Linuxbased distributed systems.
• Collaborate with engineers across runtime security and networking teams to push the boundaries of edge computing.

What Were Looking For

• 6 years of professional experience with C.
• 4 years of handson VM/compiler experience ideally with V8.
• Strong knowledge of computer science fundamentals including data structures algorithms and system architecture.
• Experience with lowlatency environments (e.g. game streaming trading systems highperformance computing).
• Operational mindset you build scalable productionready solutions.
• Deep understanding of web technologies (HTTP JavaScript WASM).

Bonus Points

• Experience working with Rust in highperformance 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 opensource projects.

This is an exciting opportunity to work on cuttingedge compiler and runtime technologies at an unmatched scale. If youre passionate about highperformance computing distributed systems and compilers wed love to hear from you!

What Makes Cloudflare Special

Were not just a highly ambitious largescale technology company. Were a highly ambitious largescale technology company with a soul. Fundamental to our mission to help build a better Internet is protecting the free and open Internet.

Project Galileo: Since 2014 weve equipped more than 2400 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 Cloudflares enterprise customersat 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 weve 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 privacycentric public DNS resolver. This is available publicly for everyone to use it is the first consumerfocused service Cloudflare has ever released. Heres the deal we dont 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.

Sound like something youd like to be a part of Wed love to hear from you!

This position may require access to information protected under U.S. export control laws including the U.S. Export Administration Regulations. Please note that any offer of employment may be conditioned on your authorization to receive software or technology controlled under these U.S. export laws without sponsorship for an export license.

Cloudflare is proud to be an equal opportunity employer. We are committed to providing equal employment opportunity for all people and place great value in both diversity and inclusiveness. All qualified applicants will be considered for employment without regard to their or any other persons perceived or actual race color religion sex gender gender identity gender expression sexual orientation national origin ancestry citizenship age physical or mental disability medical condition family care status or any other basis protected by law. We are an AA/Veterans/Disabled Employer.

Cloudflare provides reasonable accommodations to qualified individuals with disabilities. Please tell us if you require a reasonable accommodation to apply for a job. Examples of reasonable accommodations include but are not limited to changing the application process providing documents in an alternate format using a sign language interpreter or using specialized equipment. If you require a reasonable accommodation to apply for a job please contact us via email at or via mail at 101 Townsend St. San Francisco CA 94107.