Tutorial - Ranks 1-10
Early Ranks - Ranks 11-30
Supreme Researchers - Ranks 31-50
The Comrade Era - Ranks 51-69
Level 3 Supremes - Ranks 70-89
The Production Era - Ranks 90-99
The Plateau - Ranks 100-115
Starting at rank 100, comrade requirements are about double that of the 90s. It is recommended to have at least 10 M comrades per second for these ranks. This means Jym at level 4 and comrade rares (at least ore, bullets, and placebos) at level 10.
Thankfully, production does not get too much harder than the late 90s here. In fact, the next two generators, Sky Farms and Laser Drills are similar in production difficulty to Bombers, only increasing in comrades to unlock and the previous tier cost, and the generator after that, Fusion Plants, is only about twice as difficult as bombers. Thus, those missions will require upgrades in discount to complete in a reasonable number of manual crits.
After the jump in comrade requirements, the difficulty increase is much more gradual. However, it is recommended to get 8 M bonus if you haven't already to make the production missions less painful, especially 12 AAAA ore at Rank 105 and 911 UUU placebos at Rank 115. Then, focus on getting your comrade rares to max level and focus on placebos and (to a lesser extent) military, since ranks starting with 116 focus on these.