Facebook employees Mark ZuckerbergJustin Sullivan/Getty Images

It’s not impossible to land your dream job at one of the nation’s biggest tech companies — but be prepared for a long and rigorous process.

To gain insight into the interview experience at some of tech’s most important companies, career data site Comparably surveyed 6,463 current employees at Amazon, Apple, Facebook, Google, and Microsoft.

Comparably found that the process varies considerably from company to company. At Apple, candidates should “expect to be turned away a few times,” and that it might take “a few years” to land a job. But at Facebook, engineers can show up for an interview in “whatever is most comfortable,” including a t-shirt and jeans. 

Here’s how current employees rated the interview process at five of the biggest tech companies in the world.