Gumroad somewhat notably is a company that has
only part-time employees. There are some companies that do a 4 day work week, and some big companies like Google have policies where full-timers can ask to go down to 60% or 80% pro-rated, but you can't apply directly for those positions.
Are there other companies like Gumroad that offer part-time employment as a competitive hiring advantage and as a formalized program? Note I'm not asking for companies that have allowed it one-off for a key hire, or a company that hires contractors occasionally.
So take those "policies" with a grain of salt.