Vias don’t go well in pads, of course. In fact, I think it’s fair to say that vias go as well in pads as large igneous rocks go in peanut butter and jelly sandwiches.
But it’s not just vias in pads that annoy people. Vias near pads can be pretty much a nuisance too. In the SOIC pictured below, the pin 1 lead is at risk of having the solder wicked off the pad and down into the via.
If you’ve got to have a via right near a pad like that, always make sure there is something between the pad and the via that will keep the solder away. A thin line of solder mask, or even silk screen, like with the pads and vias on pins 12 and 14, will do. Anything to stop the solder from going where you don’t want it to go.
Jersey barriers, perhaps?