> I've personally worked with many junior engineers over the years and it's really hard to mentor someone over a computer screen. It's definitely possible, but being able sit down informally and talk about something that's hard to understand, or unclear is much harder remotely.

I've done this a bunch over zoom.

> I haven't figured out a virtual way to give an intern a small assignment and determine if they're struggling remotely (yet) short of doing peer programming.

Ask them in standups? Have an "open door" policy towards them pinging you to hop on a zoom? You also probably don't need to be hovering over them making certain that they're never struggling, that's a form of micro management. Gotta let the kids fight with problems for awhile before jumping in and fixing it for them[*].

[*] and really don't fix it for them, teach them how to fix it. poor phrasing.