MongoDB — Embedding vs referencing

1 Find employees in Engineering Easy 2 Find with projection Easy 3 MongoDB relationships #1 Medium 4 MongoDB relationships #2 Medium 5 MongoDB relationships #3 Medium 6 MongoDB relationships #4 Medium 7 MongoDB relationships #5 Medium 8 MongoDB relationships #6 Medium 9 MongoDB relationships #7 Medium 10 MongoDB relationships #8 Medium 11 MongoDB relationships #9 Medium 12 MongoDB relationships #10 Medium 13 MongoDB relationships #11 Medium 14 MongoDB relationships #12 Medium 15 MongoDB relationships #13 Medium 16 MongoDB relationships #14 Medium 17 MongoDB relationships #15 Medium 18 MongoDB relationships #16 Medium 19 MongoDB relationships #17 Medium 20 MongoDB relationships #18 Medium 21 MongoDB relationships #19 Medium 22 MongoDB relationships #20 Medium 23 MongoDB relationships #21 Medium 24 MongoDB relationships #22 Medium 25 MongoDB relationships #23 Medium 26 MongoDB relationships #24 Medium 27 MongoDB relationships #25 Medium 28 MongoDB relationships #26 Medium 29 MongoDB relationships #27 Medium 30 MongoDB relationships #28 Medium 31 MongoDB relationships #29 Medium 32 MongoDB relationships #30 Medium