I'm not saying you can write ANY code and code so shitty that it's slower than the database. Heck you can have the handler sleep for a minute before forwarding the request to the DB. I obviously don't mean that.
I'm talking about a specific kind of shitty code in the sense you don't have to worry about move semantics, memory management. You don't have to preallocate memory, you don't have to think about a lot of stuff and optimize for the heap or the stack. That kind of thing.
Just write some trivial non-blocking code don't worry about anything else and you're overall good. I guess "shitty code" is the wrong choice of words here. You don't need to spend time optimizing is more what I mean. If you know what you're doing it's fine... no major effort needed to change things.