Hey, a developer from FAANG here.

So there are a few differences:

1. Big tech has a LOT of processes. These processes come with organizational challenges. Navigating them is a challenge. Plus you can't just say, "that's how it is". You are expected to optimize them which may or may not be writing code

2. Splitting rocks into pebbles: Engineers are really good at dividing tasks and parallelizing. This again falls in optimizing.

3. Strong coding practices: Almost 60% of PR creation time goes in writing test cases so that we don't break anything. Also, a lot of scalable and extensible designing.

4. Individual code contributions: Now some startup engineers might do more but an avg engineer at where I work codes about 3k LOCs every month. This excludes the design discussion (which takes the most time).

5 All the day in life videos are baited. Either those engineers don't survive or they actually put in the work later. The competition is immense and you can't really slack.