In WALL-E,According according to the president's addresses EVE was part of the Axiom's crew since it first left Earth, meaning that she and WALL-E would have been manufactured around the same time since he was intended to start cleaning the planet up right after humanity evacuated.
Why then do the two have such a major difference in their looks and technological standards if they were both intended for roughly the same behind the scenes purpose (at least in terms of wandering around wastelands and looking through trash)?