In this role, you'll work directly with our CTO on the design of our large-scale, high-performance C++ quant library. You'll own performance-critical code, work on high-level library design questions, and be the on-staff C++ expert that our team trusts when something needs to be fast and correct. As part of a small, hands-on team, you'll have real ownership from day one and your work will have an immediate and outsized impact. This is a rare position for an engineer who wants to work on genuinely hard problems at the intersection of numerical software, performance optimization, and software architecture. We're a hybrid team, in the office on Tuesdays and Thursdays. **What You'll Do** - **Core library development:** Build and develop our core C++ quant library, from interface design through implementation, tests, and documentation. - **Library design:** You'll help design the internal APIs that our team uses as well as the external APIs that our clients depend on to power their trading. - **Performance work:** Investigate and profile algorithms, functions, or entire workflows to understand and improve their performance. - **Quantitative algorithms in production:** Work with our quants to implement pricing and numerical models efficiently and correctly. - **Supporting other developers:** Review code, answer design questions, and help teammates (who are strong quants or strong engineers but not always C++ specialists) write better C++. - **AI tooling:** AI development tools (Claude Code, Codex, and similar) are a standard part of how we build software here, and we'll expect you to use them well. - **Build systems and developer experience:** Cut build times, improve the test and CI setup, and improve the developer experience. **Who You Are** - You have a Bachelor's degree or Master's degree in a computer science or another highly technical discipline (physics, engineering, chemistry, etc.) - You have roughly 2 to 6 years of professional C++ experience, or comparable depth from academic or open source work. - You've worked substantially in a large C++ codebase, in industry or academia, and you're fluent in modern object-oriented and/or functional programming paradigms. - You are proficient in Python and have used at least one other systems language (Rust, C#, Java, etc.). - You care how your code reads. You write clear, concise, well-organized C++. - You are comfortable with using agent-driven development workflows to generate high-quality code. - You're careful. You test your work to know it's right, and you think through numerical edge cases before a client finds them. - You're rigorous about performance. You measure first, and you understand how the hardware affects the code you write. - You explain your thinking clearly, in code, review comments, design discussions, and writing. - You work well independently, and just as well as part of a small, hybrid team. - You are authorized to work in the US. **Nice to Have** - Hardware-aware programming: SIMD, GPUs, cache behavior, concurrency. - Active open-source contributor in the C++ ecosystem. - Experience working on an options market making or derivatives quant library, or other quantitative finance background.