One of the best interviews I've ever been through and should be a poster child of how software engineer interviews should go.
Mainly, what was good was that there were a lot of pragmatic questions about your experience and walking through code. I was coming from the West Coast where it's not uncommon to have 22 year old engineers fresh out of college grill senior engineers on inverting binary trees instead of asking them about their systems, so this was a breath of fresh air.
The engineers were very knowledgeable while also having some Midwestern humility. Ie the kind of people you want to spend 8 hours a day with. Great view of downtown St Paul too.