In this guide, I will show you where you can find the easter eggs left by the developers for themselves. In order to find all 3 easter eggs, you need to go to the hubs of all open locations. (Cetus, Fortune, Nekralisk).
After landing on Cetus, we jump to the first mountain ledge on the right.
Next, you will see the next ledge, jump onto it.
Then just run until you hit the last ledge that we need.
This is how it will look.
You just run up and press X.
Immediately after entering Fortuna, jump to the first right balcony.
Above you will see another balcony, jump onto it.
Rotate the camera so that you can see the face of your warframe, and press X on the glyph.
Upon arrival at Deimos, turn the camera slightly to the right and you will see a column. We need to jump on it.
You are almost there.
Come up and press X.
To activate this Easter egg, you need to go to the second worker and press X.
Thanks to Лёшенька for his great guide, all credit to his effort. you can also read the original guide from Steam Community. enjoy the game.