Software Engineer, RL Data

Cursor is building the future of coding. We train frontier coding agents and scale RL on real user data to make them increasingly effective.

As a Software Engineer on the RL Data team at Cursor, you'll create the tasks, rewards, and environments that train our coding agents. The team owns the data that goes into training: what the model is asked to do, how we score it, and the setups it learns in.

Designing a task set that teaches a specific agent capability, then iterating on it from traces and evals until the model actually gets better.

Reading a pile of agent traces, finding a failure mode or a surprising behavior, and building a system that surfaces more of the same.

Turning a one-off recipe into something other teams can reuse: better rewards, cleaner environments, tighter data quality.

Partnering with research on whether a dataset is actually teaching the thing we think it is.

You write careful, fast code and have strong software engineering fundamentals.

You like setting tasks: breaking a fuzzy capability into something concrete you can measure.

You have an infra, data, or distributed systems background. RL experience is a plus, not a requirement.