This is a StoneBlock 4 server running on Minecraft 1.21.1 and it is made for people who like modded survival and slow progression. The world starts in stone so you dig and unlock more stuff as you go and that is a big part of the gameplay.
The server runs on strong dedicated hardware in Europe in Belarus so it feels smooth. They even use an extra proxy tunnel through Germany so players from places like the US and Asia can get better ping and less lag. It is clearly focused on performance so it does not stutter all the time.
There is custom progression in game and you unlock things as you advance. It feels like you are always working toward the next step instead of just rushing everything at once. It is not super hardcore but you still need to think about what you are doing.
The community is pretty chill and player driven so people just hang out and help each other figure out the mods. Discord is connected to the server so ranks and chat are synced which makes talking with everyone easier even when you are not online in game.
