This sounds terrifying and like something I'd never, ever put in the tons of time to properly prep for for a single company's process just for a chance at a job, but add it to the list of things I'd much prefer to the current system if it were widespread enough I could prep only for that.
If it’s a topic of your choosing, a lot of engineers who aren’t super junior probably have a lot of the fixins for a short technical talk on something of interest even if they haven’t presented at a conference. And even juniors probably have something from school.
Added: I should acknowledge though that talking about technical topics of interest may get more complicated at some proprietary firms than open source ones.
