What trigger your decision to change employer?

Rami, sometimes it is hard to compare every thing little sacrifices one must give to gain overall required change

Yes, under the work environment many things, the most important of which is the routine, lack of gradualism , career, motivation,developpement , et

Poor working environment is the worst enemy

agree with some points. No appreciation and recognition- feeling the importance of whatever you do for n number of hours

I want to point out that the root of needing to change is often based on my ability to make it better. An environment may not be good. Can I improve it? I once was in a situation where there were 2 managers on a project (front-end development and back-end development) and they were not communicating. I asked to join the project and then proceeded to do everything in my power to bridge that communication gap. It worked. Conditions for everyone improved. I have been in positions where I was frankly bored. I set up additional projects for myself, research projects, training projects, etc.
But when you find yourself in a situation where things are bad and you have no power to make them better, then it is time to move on.