Engineer, About

Masters of mechanical mayhem, engineers love to tinker with explosives, elixirs, and all manner of hazardous gadgets. They can take control of an area by placing turrets, support their allies with alchemic weaponry, or lay waste to foes with a wide array of mines, bombs, and grenades.

"Engineers are technological and alchemical masterminds. They employ turrets, grenades, elixirs, a variety of other impressive devices, and concoctions to overcome their enemies. As an adventurer profession, engineers wear medium armor."

http://metabattle.com/wiki/Engineer
http://wiki.guildwars2.com/wiki/Engineer