alt Hacker NewsIMO interviewing is the biggest bottleneck and if interviewing was decoupled from hiring then it wouldn't be a problem. But this requires a Guild-like organization to manage interviewing/vetting and for companies to use said Guild for hiring. The companies could then do a single team culture meeting (if they wanted) before hiring.
I wish I could remember who, but there is a company out there who conducts tech interviews to create a pool of candidates for their customers. Pretty sure there was a post here about it, but it's lost in my ocean of unread favorites.