By "cloud computing expert", do you mean Amazon sales shill? It's weird enough that someone on HN would just use that vague credential of "expert" in the first place, but this thread is ridiculous ('round here, usually we recognize experts when they say something along the lines of "Hi, I'm the guy discussed in the article...", or "Hi, I actually wrote that software 15 years ago...").
You know that Snap can hire more than 3 people, right? They can have people working on the infrastructure at the same time that someone else works on "the product" they want to build. That's what happened at Google, and as a side effect, they now have a cloud platform they can rent out.
There are some benefits to using cloud services in some cases. It's rare that 100% cloud is a wise deployment move, especially for companies that operate at Snap-scale.
That's the point I'm trying to make. Snap has, say, 100 employees + $2b. The 100 employees are working on features. The $2b can now go to Google, or to purchase "focus" for in-house infrastructure, there is no slow down in developing features. Now if they can't technologically duplicate what they need using $2b is a different story which I have no opinion on.
They don't just have to build it though; they have to build it fast enough to handle their growth. $2B might not be enough (or it might not even be possible for any amount) to build what they need fast enough to not hamper growth.
Also, by buying from Google, they hedge against lower than expected growth too. If growth doesn't meet expectations, while they're still obligated to spend the $2B, they can re-sell the services for likely close to cost, given they'll be getting a discount.
