What hosting characteristics should be emphasized when creating a callback?

Question

Network administration

I am writing a callback server for VK. Usually these are simple operations (regular parsing, writing / reading from the database), but there are also complex, lengthy ones (waiting for a response from another server). There are a lot of requests - 40-50 per second is a normal load, and 100-120 is a peak one. What to focus on when choosing a server?

Answer 1

You write the server callback directly on VK, contact VK, maybe they will hire you, because they have only one callback ...
But in fact, you didn’t even indicate which language you write.
In any case, take a simple vds, install nginx, and then what you need (php, nodejs, etc ..). At any time, you can get resources if you don't have enough.
I process ~ 5 million requests per day on 2x2.4 and 2GB of RAM, all sessions are stored in mysql, which eats up a large amount of memory, but about 700mb remains free.