Did you use your FAANG status to negotiate an unusually high salary? Perhaps they acquiesced to your demands under the condition they would evaluate your perfor

Did you use your FAANG status to negotiate an unusually high salary? Perhaps they acquiesced to your demands under the condition they would evaluate your performance to see if you were worth the high price. That is, the founders may have said something to each other along the lines of "well, he's really expensive but maybe he's worth the price if he performs equivalently to 2-3 engineers. Let's hire him for a month or two and see how it goes." Did you ask for an outsized salary and then perform poorly (or even "averagely") during the trial period? This might explain it.