Is this the first time you've heard the term serverless? It means your code is plug & play, you don't have to manage the infra (I.e. a server) yourself.

The "API server" only runs when requests come in. Otherwise Modal scales everything down to 0, and you don't pay for anything. It's similar to putting Lambda behind an API gateway.

I think serverless just means that you hire less devops people for your specific team.

It’s a cost-saving measure that costs you mortal wounds in integration expense, and eventually building out a real infrastructure plan.

"serverless" is a throwback to 2013 a decade ago when it was a novelty to not know where your servers were or what they were made of, some people never move on. but in this case, this is a company advertising their serverless architecture for that specific crowd.

this is distinct from "client side" where no servers are involved, aside from maybe something that serves a static web page.

Because the resources are on demand, and the provider takes care of all the server management.

https://en.wikipedia.org/wiki/Serverless_computing