how to get promoted quickly?
1. Get effecient at fixing bugs and making changes. Get exceeds or better for a half before promo. 2. Get your manager and TL to set you up with a "L4 promo project" 3. Write a design doc and deliver that project. If it moves a metric that's good too. 4. $$$ Source was at Google for a long time.
By working hard
Asking for specifics... for example at fb it’s all about showing impact.
Ehh E4 at Facebook doesn't really need "impact" you need to operate/execute sanely. If you had very little say in what work got done, you are more evaluated on how the work got done not the impact of the work. That said, impact makes it easy to show that you operated effectively.