(disclaimer: I work at Google)
Google is a great company to work for, but there are many great companies out there. Don't close off other possibly-great opportunities because you're focused on working for a single place. Some random thoughts:
- Hiring at Google, despite our best efforts, is a mostly-random affair. The process is optimized to avoid hiring bad engineers, at the expense of frequently rejecting good engineers. If you get rejected, it doesn't mean anything.
- The average kind of eng work at Google is much like that at any other extremely well-run coding shop. You may spend a lot of time working on backend code that unglamorously glues two communications protocols together. It won't require a deep knowledge of fancy algorithms, but it will require a dedication to code quality, sustainability, testing, and personal productivity.
- Or you may get to work on the Next Big Thing, but keep in mind that most NBTs never see the light of day. It's an exciting work environment, but you have to deal with a lot of chaos and a lot more politics and uncertainty.
- The benefits are great, the work environment is great, and the average quality of your coworkers is great. This is the best thing about Google. If I were going to work somewhere else, I would prioritize these aspects.
- Google, like all large companies, is an uneven experience. Some excellent engineers get hired here who never really "click" -- they get put on projects they don't find interesting, they don't get on with their coworkers, etc. The vast majority of your coworkers will be really outstanding, but there will always be at least one person who you think is kind of an idiot. Most managers are great, but there are still a few assholes. If yours is, then you won't have a good time. Google does its best to minimize all of these problems via things like how it handles promotion, but there's only so much it can do.
Long story short: self-improvement is its own reward. Doing things is how you prove the truth of that improvement. If you can combine that with a great work environment, you're pretty set.