Overview

Senior Software Engineer, Workers Runtime. The Workers Runtime team delivers features and improvements to our Runtime which executes customer code at the edge. We care about performance, JS API surface area, WebAssembly support, and scaling securely and efficiently.

We are looking for curious and empathetic individuals who are committed to developing themselves and learning new skills. We hire the best people based on potential and support them throughout their time at Cloudflare. Available locations: Austin, TX | Lisbon, Portugal | London, UK.

What You'll Do

You will join a team of engineers building innovative products that bring security and speed to millions of internet users. You will help shape product features based on technical feasibility and ensure the company meets ambitious engineering goals. You will balance business needs with technically innovative solutions, shifting between big-picture goals and technical details in a fast-paced environment.

Qualifications & Desirable Skills

• 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 own it in production.
• Deep understanding of the web and technologies such as web browsers, HTTP, JavaScript and WebAssembly.
• Experience in low-latency real-time environments (e.g., 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.

Bonus Points

• Experience building high-performance distributed systems in Rust.
• Experience with cloud platforms, especially serverless platforms.
• Experience with JS engines (V8, SpiderMonkey, or JavaScriptCore).
• Experience with standalone WebAssembly runtimes (Wasmtime, Wasmer, Lucet, etc.).
• Deep Linux/UNIX systems, kernel, or networking knowledge.
• Contributions to large open source projects.

What Makes Cloudflare Special

We strive to protect and strengthen the free and open Internet. We support initiatives like Project Galileo, Athenian Project, and 1.1.1.1 to improve safety, reliability, and privacy for users worldwide.

Equal Opportunity & Accommodations

Cloudflare is proud to be an equal opportunity employer. All qualified applicants will be considered for employment without regard to race, color, religion, sex, gender identity, gender expression, sexual orientation, national origin, ancestry, citizenship, age, disability, or any other protected basis. We provide reasonable accommodations to qualified individuals with disabilities. If you require an accommodation, please contact hr@cloudflare.com or the postal address listed below.

Project Galileo and other initiatives are described above. This position may require access to information protected under U.S. export control laws. Offer of employment may be conditioned on authorization to receive software or technology controlled under export laws without sponsorship for an export license.

Location: London, United Kingdom; posting date: 2 days ago.