Level 37

Total Experience Required 238,579 [confirmed]

Level 100 progress: 3.5%

This is roughly:
Killing 796 people in Warzone, or...
Killing 812 people in Execution, or...
Killing 674 people in Wingman, or...
Scoring 170,414 points in Guardian, or...
Scoring 518,650 points in Annex, or...
Scoring 313,920 points in Submission.

Horde (TU4)

Completing 1,193 waves on Casual, or...
Completing 796 waves on Normal, or...
Completing 597 waves on Hardcore, or...
Completing 478 waves on Insane.

Or a combination of the above. Have fun!