Complex sentence: O'Brien auditioned for a spot as a cast member for both 2005 and 2009; the latter resulted in the writing job: he has been a writer since the 2009--10 season.
Split into simpler sentences: O'Brien auditioned for a spot as a cast member for both 2005 and 2009. The latter resulted in a writing job: He has been a writer since the 2009--10 season.