Long ago, folks building circuit boards started out with UV lights, copper clad boards and resist pens. Now double sided PCBs are cheap and quick to order, with 4-layer boards very quickly approaching the same.
This opens up opportunities to use denser chip packages such as QFN and BGA (Ball grid array).
Dismissed by many as "too hard", "scary" or just simply too involved, designing boards with BGAs on them isn't as hard as you'd think. Various aspects of design, assembly, and rework will be covered. If you design boards but haven't used BGA parts yet and don't know what "dogbone" or "ballout" mean, you should gain something from this talk.