Jumping on the bandwagon here when it comes to having extensively used both, I second the "Interac/Fax - Pix/Internet" analogy.
I won't get into the actual implementation details of both solutions, but the way Pix changed the finance landscape of Brazil is something else.
The major difference for me personally is the fact that Pix transfers are instant as in instant messaging instead of Interac's (more often than I'd like) 30min transfers.
Also, paying anything via Interac is kind of awkward compared to Pix's UX flows implemented by Brazilian banks. Can't quite explain it but it's there. Pix is one of the things I miss most from Brazil, and I'm glad Canada's Interac is as prevalent as it is otherwise it'd be a huge step down.
On the UX aspect, Brazil’s central bank has a heavy hand over the PIX experience, going as far as publishing the UX Guidelines[1] as Banking Regulation.
I won't get into the actual implementation details of both solutions, but the way Pix changed the finance landscape of Brazil is something else.
The major difference for me personally is the fact that Pix transfers are instant as in instant messaging instead of Interac's (more often than I'd like) 30min transfers.
Also, paying anything via Interac is kind of awkward compared to Pix's UX flows implemented by Brazilian banks. Can't quite explain it but it's there. Pix is one of the things I miss most from Brazil, and I'm glad Canada's Interac is as prevalent as it is otherwise it'd be a huge step down.