Job Listing With Filtering Done with React

This project went pretty well overall.

I had some problems with the data fetching at first, so my first question would be : are there better ways to fetch the JSON data in this project (maybe use a context instead of fetching it twice maybe?)

My next question is : how should I create responsive websites with react?

-Is using the window width and a useEffect hook in the app component good enough and bug free?

-If not, I would really like to know how to do it the better way.

There's probably lots of accessibility problems as well, which id like to hear about.

The website has a pretty slow load speed, is there anything in my code that makes it slow?

Thank You for reading and (maybe?) helping me :)