From the Traveller RPG wiki on wikia.com:
Lester Smith gave up three different, entirely reasonable careers in order to pursue an occupation (perhaps more accurately, a preoccupation) as a game designer.
An alumnus of Game Designers' Workshop, he worked full-time in the hobby as lead designer for the 2300 AD role-playing game. He worked on several Twilight: 2000 supplements and many Space 1889 projects, designed the Dark Conspiracy horror RPG and many of it's supplements, and contributed to the initial work on the Traveller: The New Era RPG.
Les then moved to TSR, where he began work as designer of the Bughunters RPG, part of the short lived Amazing Engine line of games, and designed the Origin-award winning Dragon Dice.
Shortly thereafter, Les left TSR to help Ken Whitman in the relaunch of the Traveller RPG line by Imperium Games.