YC asks primarily questions about the company applying (but also has founder profiles attached). This A16Z program only asks questions about an individual applying, and seems most interested in their corporate pedigree.

The "Meet our STARTers" carousel shows: Cofounder of Rappi, Former Global Head of Ecommerce at Rappi, Former Business Unit Head at Rappi, Former VP Product at Ethos, Former Chief Strategy Officer.

It appears to be something like an open invitation for a "Entrepreneurs in Residence" type program than a YC-style startup program.

A lot of VCs think hiring the executive team at a successful startup is a good recipe for success. As far as I know this hasn't proven to be true, although of course there are surely some examples.