Level 33

Total Experience Required 171,380 [confirmed]

Level 100 progress: 2.51%

This is roughly:
Killing 572 people in Warzone, or...
Killing 583 people in Execution, or...
Killing 485 people in Wingman, or...
Scoring 122,415 points in Guardian, or...
Scoring 372,566 points in Annex, or...
Scoring 225,500 points in Submission.

Horde (TU4)

Completing 857 waves on Casual, or...
Completing 572 waves on Normal, or...
Completing 429 waves on Hardcore, or...
Completing 343 waves on Insane.

Or a combination of the above. Have fun!