This is Create: Steel century, an extremely optimized modpack featuring Create , Tinker Construct and various addons for both the mods. For example Create: The Factory Must Grow , Create Big Cannons , Tinkers Integrations and Tweaks and many more!

SMALL TUTORIAL

Create: Steel century is mostly a tech modpack, but it's possible to play by your own rules!
Tinker Construct gives many manual options for your crafts, and is your main source of self defense. Tinker construct lets you make tools weapons and armors out of many materials using its worktables, melter, alloyer, smeltery, and foundry. You can get more information about it in its in game tutorial books or its page.

If you really want to get some automation going, you need Create. As you may already know, Create is a steampunk themed mod wich lets you automate many things, and with its addons, almost everything I would say! It is based on rotational force, which you can get from things like waterwheels, windmills and steam engines. you can transport this energy trough shafts, belts, cogs and chain conveyors and many more ways. You can get more information about it on its page or tutorials (for example this one).

The objective of the modpack is to make factories, mega bases and (in multiplayer) faction based PVP

Also, there is a final boss, an upgraded wither from Wither: Reincarnated which you are supposed to fight after the ender dragon, which I also upgraded trough True Ending ~ Ender Dragon Overhaul.

Create Steel Century