Hot take (& a bit biased) but I think it's extremely valuable to work at FANG or another big co early in your career. 

Lets you establish a great foundation (mature infra & coding practices), lots of smart minds you can learn from, high salaries, etc. 

Learning & growth gets capped so only valuable at the start tho.

cma.xyz. Founder /paragraph, ceo /mirror, previously at Google & Coinbase 

When I started my career, I thought startups were the only way.

Later, Pinterest acquired a startup I was working for and I learned things:
1. they do have bloat
2. but they have insane talent (really didn't think this was true)
3. they teach you best practices
4. actually work with real scale

 ~4 years seems enough