Not sure how they map to other companies, but it's a 10 level system. New grad non-engineers start at level 1. New grad engineers start at level 3. CEO is level 10. VP eng is level 9 I think. Engineering L4 is ~2.5-3 yoe. L5 is ~5-7 yoe. Most engineers are expected to plateau at L5. L6 is engineering manager. L7-L8 is director.