# Senior Software Engineer, Workers Runtime

**Company:** [Cloudflare](https://hotfix.jobs/companies/cloudflare)
**Location:** Unspecified
**Role:** Backend Engineering
**Experience:** 5+ years
**Skills:** Rust, C++, Webassembly, JavaScript, Linux, Http, V8, Spidermonkey, Javascriptcore, Wasmtime, Wasmer, Lucet
**Posted:** 2026-07-10

> Build and improve Cloudflare Workers Runtime: enhance performance, reliability, JavaScript and WebAssembly support for edge execution of customer code. Requires strong CS fundamentals, production ownership, and 2+ years C++/Rust experience.

## Job Description

## Responsibilities
- Build features and improvements for the Workers Runtime.
- Improve runtime performance, reliability, and scale.
- Expand JavaScript API and WebAssembly support.
- Help shape features based on what is technically possible.
- Own code in production and debug issues in a large-scale distributed system.
- Work in a fast-paced, iterative environment that balances product goals with technical execution.

## Requirements
- 2+ years of recent professional experience with C++ or Rust.
- Strong computer science fundamentals, including data structures, algorithms, and software design.
- Operational mindset and experience owning production systems.
- Deep understanding of the web, including HTTP, JavaScript, and WebAssembly.
- Experience debugging and optimizing large-scale Linux-based distributed systems.

## Nice-to-Haves
- Experience building high-performance distributed systems in Rust.
- Experience with cloud or serverless platforms.
- Familiarity with JS engine internals such as V8, SpiderMonkey, or JavaScriptCore.
- Experience with standalone WebAssembly runtimes such as Wasmtime, Wasmer, or Lucet.
- Deep Linux, UNIX, kernel, or networking knowledge.
- Contributions to large open source projects.

## Similar roles

- [Senior Software Engineer, Backend](https://hotfix.jobs/jobs/d19a9ae5-b1cd-40fe-afff-6dcc58bb0c2d) - Payabli - Remote
- [Senior Backend Engineer](https://hotfix.jobs/jobs/4b7e2c83-fc89-4cec-bff5-78a5c1cfc2d7) - Aurelian - Seattle, WA - $160k – $220k/yr
- [Senior Software Engineer, Backend](https://hotfix.jobs/jobs/aae445f1-8e62-4e47-8923-15cf530d3bb7) - Vector Legal - Remote - $180k – $200k/yr
- [Software Engineer, Backend](https://hotfix.jobs/jobs/542f1aa3-f562-44e7-a8de-caf3d127868d) - Mercor - San Francisco, CA - $200k – $500k/yr
- [Senior Engineer I](https://hotfix.jobs/jobs/27bec17a-807b-46f4-8110-b6ebd64a2c31) - SimplePractice - Santa Monica, CA - $215k – $215k/yr

**Apply:** https://hotfix.jobs/jobs/906c6376-3bcb-46e3-ac03-78a64804ba8d
**Canonical:** https://hotfix.jobs/jobs/906c6376-3bcb-46e3-ac03-78a64804ba8d