The Giant Bomb Wiki says he was born 07/26/1985, so he'll turn 31 in a few months.
Edit: Here are is the Giant Bomb Wiki list of birthdays:
Jeff Gerstmann: 08/01/1975 (Currently 40)
Jason Oestreicher: *
Vinny Caravella: 05/10/1978 (Currently 37)
Brad Shoemaker: 07/20/1979 (Currently 36)
Matt Rorie: 11/10/1979 (Currently 36)
Alex Navarro: 11/18/1981 (Currently 34)
Dan Ryckert: 06/16/1984 (Currently 31)
Austin Walker: 07/26/1985 (Currently 30)
Drew Scanlon: 05/19/1986 (Currently 29)
*Jason does not have a wiki entry yet, but in 2015, he mentioned his first son was 22 years old and that Jason was 16 when his son was born. Going by that math, he was about 16 years old in 1993 (22 years before 2015). Being 16 in 1993, would mean he was born in 1977, making him 38/39.
Is this what Doxx'ing looks like?