We're biased in favor of hiring people who can work with us in person, but regardless I highly recommend getting started via the open source framework mentioned above -- you'll connect pretty tightly with the team, get a sense for how we work, and can figure things out from there.

Plenty of our coolest, most interactive exercises were contributed by remote open source contributors.

In-person is strongly preferred, but remote is a possibility for the right person -- there are a couple of employees who work full-time remotely.

If you're looking for something less formal, here's information about volunteering and helping to make exercises:

https://github.com/Khan/khan-exercises/wiki/Getting-Involved