Some generic Shimano disk brake, I think BR-something. Got BOS1 brake pads on it. I don't commute on it, but definitely ride at least a few hundred kilometers on it a year. They aren't particularly performant, you should always be able to lock up hydraulics with a single finger if they are adjusted correctly imo. Even my mechanical avid BB7 disks I could lock up with a finger when my brake cables were newer.