A Tileable Mobfarm designed by me; Spiders may become a trouble, but other mobs will push them or they will despawn.
The main file its 4 floors (3 Tiles, 1 Top Tile) and you can add as many as you want.
It uses fans to push mobs and also fans with fire to kill them with fire (for that I used Create: Connected, but i added saws in case you dont want to add it or a witch spawns), everything goes to a vault that can be extended (in the schematic its a 3x3x1 vault), it works at 120RPM. Hope you like it!