I disagree, it's a much more helpful way to let them explore the code base than "here, write a test for some feature you also don't understand". Where I was it

I disagree, it's a much more helpful way to let them explore the code base than "here, write a test for some feature you also don't understand". Where I was it was never a stated goal to have them ship asap, the goal was a) to let them learn quickly and b) let them not hate their new job. Incidentally, everyone except one person liked this approach. Hands-on, have the genuine feeling to do something sensible (maybe not important, but hey, it's your first week) and NOT spend 2w just reading docs.