About the Position We're looking for software engineers and researchers to establish a new Formal Methods team at Jane Street. With the emergence of agentic programming, we think formal methods will play a major role in providing feedback for agents and helping validate agent-generated code. Our vision is to make formal methods as useful a tool for building software as type systems are for us today, both by leveraging existing tools and technology, and pursuing novel approaches. We're looking to build a new team with engineers who have: • Deep experience with formal methods. There's no specific checklist. We're broadly interested in people with backgrounds in interactive proof assistants, automated theorem provers, static analysis, refinement types, program logics, property-based testing, and related areas. • Top-notch software engineering skills. We're looking for people who can turn cutting-edge research ideas into practical tools, and get these tools in use across the firm and beyond. • Strong interpersonal skills. Software engineering at Jane Street is highly collaborative, and we're looking for people who can work effectively in small, close-knit teams. We are interested in exploring a wide variety of approaches. While we are eager to integrate new tools into our existing infrastructure, no previous experience with OCaml or functional programming is required. Why do it here? The whole world is thinking about what agents mean for the future of programming, and there's no shortage of efforts trying to mix formal methods and agents. But think there are things about Jane Street that make this a unique opportunity. First, we have deep control of the language we're using, which lets us shape it into a better home for proof-oriented techniques. We can adjust the language and the proof system at the same time in ways that aren't possible when you have to take the language as given. Second, we have a community of programmers who are eager to adopt new tools, and have the right intellectual toolkit to do so. That community is an unparalleled source of both feedback and leverage for the work we do here. We're in the early stages of building this team, with an enormous amount of work ahead of us, and we'd love you to be a part of it.