First, working in Google, Facebook, Amazon, or Twitter is overrated more likely than not. Remember that. You don't really need to work in a big company to have fulfilling job that allows you to grow professionally and pays decently. (Don't be greedy.) Second, remember that interviewing is both way lane. It's not only a way for employer to assess candidate, it's a way for a candidate to assess the potential employer.…
Offtopic: The 4th big is twitter? I thought it was Microsoft. I also thought that there are at least a dozen companies above twitter as far big goes in any possible sense (revenue, salaries, dev happiness, etc.).
1. Apple 2. Alphabet 3. Microsoft 4. Berkshire Hathaway 5. Exxon Mobile 6. Amazon 7. Facebook
If we're going by impact on tech, opportunities for software development, etc., it could potentially be different.