Senior Software Engineer, Workers Runtime

Position Title: Senior Software Engineer, Workers Runtime

Austin, TX | Lisbon, Portugal | London, UK

At Cloudflare, we are on a mission to help build a better Internet. Today the company runs one of the worlds 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 Magazines Top Company Cultures list and ranked among the Worlds Most Innovative Companies by Fast Company.

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 e join us!

Emerging Technologies & Incubation (ETI) is where new and bold products are built and released within Cloudflare. Rather than being constrained by the structures which make Cloudflare a massively successful business, we are able to leverage them to deliver entirely new tools and products to our customers. Cloud flares edge and network make it possible to solve problems at massive scale and efficiency which would be impossible for almost any other organization.

The Workers Runtime team delivers features and improvements to our Runtime which actually executes customer code at the edge. We care deeply about increasing performance, improving JS API surface area and compiled language support through Web Assembly, and optimizing to meet the next 10x increase in scale. The Runtime is a hostile environment - System resources such as memory, cpu, I/O, etc need to be managed extremely carefully and security must be foundational in everything we do.

We are looking for a Systems Engineer to join our team. You will work with a team of passionate, talented engineers that are building innovative products that bring security and speed to millions of internet users each day. You will play an active part in shaping product features based on whats technically possible. You will make sure our company hits our ambitious goals from an engineering standpoint.

You bring a passion for meeting business needs while building technically innovative solutions, and excel at shifting between the two understanding how big-picture goals inform technical details, and vice-versa. You thrive in a fast-paced iterative engineering environment.

• At least 2 years of recent professional experience with C++ or Rust.
• Solid understanding of computer science fundamentals including data structures, algorithms, and object-oriented or functional design.
• An operational mindset - we don't just write code, we also own it in production
• Deep understanding of the web and technologies such as web browsers, HTTP, JavaScript and Web Assembly
• Experience working in low-latency real time environments such as game streaming, game engine architecture, high frequency trading, payment systems.
• Experience debugging, optimizing and identifying failure modes in a large-scale Linux-based distributed system.

• Experience building high performance distributed systems in Rust.
• Experience working with cloud platforms, especially server‑less platforms.
• Experience with the internals of JS engines such as V8, Spider Monkey, or Java Script Core
• Experience with standalone Web Assembly runtimes such as Wasmtime, Wasmer, Lucet, etc
• Deep Linux/UNIX systems, kernel, or networking knowledge
• Contributions to large open source projects

We’re…