Software Engineer, Systems - Claude Code

Responsibilities Design, build, and optimize core systems inside Bun and Claude Code—runtime internals, I/O paths, memory management, and the agent execution loop Drive down memory usage, latency, and startup time across Claude Code and the Bun runtime Dig into performance problems across the stack: profiling, tracing, and fixing issues anywhere from the kernel interface up through the JS engine to the agent layer Collaborate with researchers and product engineers to make sure model capabilities translate into a fast, reliable developer experience Contribute to the Bun runtime and toolkit, which underpins Claude Code, the Agent SDK, Cowork, and other internal Labs products Stay ahead of advancements in runtimes, compilers, and AI‑assisted tooling—experimenting, measuring, and bringing the best ideas into our stack Qualifications Have a strong background in C and/or C++ and Rust (Zig also welcome) Have deep systems programming experience: syscalls, Linux internals, I/O (kqueue, epoll, io_uring), manual memory management, and performance engineering Have worked on language runtimes, virtual machines, compilers, or JS engines like JavaScriptCore or SpiderMonkey Have 5+ years of work experience Compensation Annual Salary: $320,000 — $485,000 USD Logistics Minimum education: Bachelor’s degree or an equivalent combination of education, training, and/or experience Required field of study: A field relevant to the role as demonstrated through coursework, training, or professional experience Minimum years of experience: Years of experience required will correlate with the internal job level requirements for the position Location‑based hybrid policy: Currently, we expect all staff to be in one of our offices at least 25% of the time. However, some roles may require more time in our offices. Visa sponsorship: We do sponsor visas! However, we aren’t able to successfully sponsor visas for every role and every candidate. But if we make you an offer, we will make every reasonable effort to get you a visa, and we retain an immigration lawyer to help with this. Benefits We offer competitive compensation and benefits, optional equity donation matching, generous vacation and parental leave, flexible working hours, and a lovely office space in which to collaborate with colleagues. Guidance on Candidates' AI Usage: Learn about our policy for using AI in our application process. #J-18808-Ljbffr United States Digital Space LLC