Q:

Can front-end to do something when 500 internal server come because a lot of access in the same time

I know maybe this is a strange things to ask but I'm quite curious about this,
"Is there any way for front-end especially in angular to help when 500 internal server error appear because a lot of access in the same time?". 
this is new for me when build a website that have a lot of traffic in the specific time such as when an assignment deadline come so a lot of user access it in the same time.
because I want to help my friend who dealt with the server so maybe there is something I can do with front-end especially when I use angular 7. I mean except change the server because we already tried to upgrade it 2 times

A:

As the front end I think the first thing you need to do when you're seeing 429 (too many requests) or 5xx (internal errors) is to limit your retry rate. Since if the server fault is due to flooding, that's the best way you can help. 
From a UX perspective, there are other things you can do, such as serving local data (taking the progressive web app approach). PWAs are a topic on their own, though.

