Derogatory term for a corporate employee
Solution 1:
You could try drone:-
A person who does tedious or menial work; a drudge: "undervalued drones who labored in obscurity" (Caroline Bates).
if you wanted to emphasize the drudgery and hopelessness of the individual, or perhaps a wage-slave
A wage earner whose livelihood is completely dependent on the wages earned.
to emphasize the helplessness of the individual, or a droid:-
A mobile robot or automaton, especially one that resembles a human.
if you wanted to emphasize any mindlessness that might be involved.
(All these from the Free Dictionary).
Solution 2:
As a British native speaker, I would have thought that "suit" or "corporate suit" would be a derogatory term to describe someone who works in a large international business corporation. Emphasizing that the person is instantly replaceable and anonymous, nothing more than the suit they are wearing.
Edit: Just thought, in the same vein, I've also heard "empty suit" in this connection.
Solution 3:
OP seeks an answer that satisfies the following 4 criteria:
1. a derogatory term or expression
2. for a low-level employee ["insignificance of the person"]
3. of a large international corporation
4. whose work is boring, repetitious and mindless ["following characteristics: boring, repetitious and mindless work"]
MINION noun: plural noun: minions: a follower or underling of a powerful person, especially a servile or unimportant one.
synonyms: underling, flunky, lackey, servant, hireling, vassal, stooge, toady, sycophant
from Google link
common N. American minion
Solution 4:
As was suggested in a comment by @DevSolar, consider cog
A subordinate member of an organization who performs necessary but usually minor or routine functions.
American Heritage
Oxford Dictionaries Online uses cog with this meaning as part of a phrase
a cog in the (or a) machine (or wheel): A small or insignificant member of a larger organization or system: copywriters have been seen as just a cog in the big advertising machine