Just got killed by endless waves of grunt and swarmers and hunters, I wonder why they always know where I am even no watcher can see me? Its so hard to survive in factor when there is not enough propulsion around.
The usual suggestion is to join the discord, they will be able to help you. However, they will need more information about your situation to help.
You have reached Factory which is fairly far if you're new to roguelikes and Cogmind in particular, and starting to get dangerous if you're not prepared. It's worth reading the survival advice in the manual, thinking about which slots to evolve and watching your moves. Propulsion can act as poor man's armor -- you can get quite far if you evolve only prop slots, stay on core hover which has a base speed of 50, about 2.5 times as fast as most enemies (if you keep all propulsion deactivated you will be on core hover) and equip propulsion only as poor man's armor.
Enemies which are faster than you may have moved into your PoV and noticed you immediately; note also that most watchers can see farther than you can without visual processors. Also enemies that spot you do notify other nearby enemies, even if they aren't watchers. (Watchers notify a larger radius.) A strong enough transmission jammer will stop this. It's also possible you're hacking machines and triggering investigations to be dispatched to the area. In that case they don't know where you are but they will be sent to the area of the hacked machines. There's an announcement in the log when this happens.