I was under the impression that designing levels was not a huge demand, also that it isn't tremendously difficult, and that was why there isn't really a set 'team.' I seem to recall that Dusty has done level work in the past, from a comment regarding the random-wall cave level when the community had asked for additional pyrat levels way back when.
Notice that, while the GP, GFX, and general application notice is sent around from time to time, you never see a 'LAT is hiring' message.