Is this sort of complexity common? I'm not saying I think it's bad, as I am sure it's all there for a good reason, but it just seems like so many services to bounce through before a web page is even served.
Google, of course, is in a class way above all those. I'm not sure if anyone actually knows how many services a single search hits now - perhaps some of the old-timers who're now VP level or above in search. The last public figures I was aware of were "hundreds of distinct services spread across tens of thousands of machines".
Most startups that actually do something useful require far more than a web frontend and a database.
Could you point me to more complex examples?
There's a very long discussion, somewhere, of Amazon's eventually-consistent architecture that I'd say is definitely on the high-complexity side of things. Unfortunately I can't find the link I'm thinking of, at the moment.
Of course, when you actually go to found the company, you should forget all that scalability nonsense and start with the simplest system possible. However, it's worth having an image in your head about how the system will evolve and what the appropriate response to various scalability challenges is.
As far as complexity goes, I believe Amazon touches some hundred something services before a page is even served. It's no surprise that they decided to make some of that into a business and start charging for it.