The role involves designing, building, and optimizing core systems within the Bun runtime and Claude Code. The engineer will focus on improving performance by reducing memory usage, latency, and startup times across the stack. Responsibilities include investigating performance issues from the kernel interface up to the agent layer. The position requires collaboration with researchers and product engineers to ensure model capabilities translate into a reliable developer experience. Additionally, the role contributes to the Agent SDK and other internal projects by maintaining and enhancing foundational tools.

Candidates must possess at least five years of professional experience and a strong background in C, C++, and Rust. Deep expertise in systems programming, including Linux internals, manual memory management, and performance engineering, is required. Experience working with language runtimes, compilers, or JavaScript engines is also necessary. A bachelor's degree or an equivalent combination of education, training, and experience is the minimum educational requirement.