Gopuff interview questions

Island of 1's, what happens when you type in google.com. I was asked to design a shopping cart, and we went through that exercise. I was then asked how could we scale it to hundreds of millions of users. I discussed micro-services, tenancy models, caching, using large scale DBs, and more. The answer they were looking for is "use a no-sql db", not a realistic conversation on what supporting that kind of user base takes.