How will the spinoff fit into the larger Doctor Who universe?

Den of Geek had a chance to chat with Doctor Who's Peter Capaldi and Steven Moffat at last weekend's New York Comic Con, and to ask specifically about their roles in the upcoming Doctor Who spinoff Class, premiering in the U.K. on October 22nd.
We already know that Capaldi will be appearing as The Doctor in the first episode of the show set at Coal Hill Academy, but what will that look like? Capaldi couldn't tease a lot, but here's what he had to say about the show in general and its relationship to the larger Doctor Who universe...
I think it’s always excited to see The Doctor from another perspective and also The Doctor's universe from another perspective. It always kind of interested me as a kid what went on when the show wasn’t on, you know? When the show had its hiatus, where was The Doctor then? What was he getting up to? Because I’m sure the season was not just a recounting what happened during the hiatus. Something went on when we didn’t see him. So, in a way, Class gets into some of that, into what’s going on when he’s not doing the regular show. But then they go off and do their own thing, which is very exciting.
Capaldi also classified the show as "quite hardcore Doctor Who," which matches up with all of the darkness, intrigue, and excitement we saw in the Class trailer, which premiered at NYCC and you can check out over at our Class news hub.
Moffat also gave us some insight into his role on the show, saying:
I'm an exec on the show, but Patrick [Ness] is showrunning, in effect. He's doing the main narrative. I'm [looking] over the scripts, I'm over the edits and all that. but I’m taking a considerable step back from where I am on Doctor Who and Sherlock. But that's because a kitchen only has so much room for too many chefs, so I leave a lot of it to Patrick. But I'm [looking] over it. I know about it.
We're really excited to see what the Doctor Who spinoff has to offer, and how it will fit into the larger Whoniverse. We had a chance to talk to the excited cast and showrunner at NYCC, so stay tuned to Den of Geek for more Class info.