Process request and return response in chunks

I'm making a search agreggator and I've been wondering how could I improve the performance of the search.

Given that I'm getting results from different websites, currently I need to wait to receive the results for each provider but this is done one after another so the whole request takes a while to respond.

The easiest solution would be to just make a request from the client for each provider, but this would end up with a ton of request per search, (but if this is the proper way I'll just do it.)

Why I've been wondering is if there's way to return results everytime a provider responds, so if we have providers A, B and C and B already returned results then send it back to the client. In order for this to work all the searchs would need to run in parallel of course.

Do you know a way of doing this?

I'm trying to build a search experience similar to SkyScanner, that loads results but then you can see it still keeps getting more records and it sorts them on the fly (on client side as far as I can see).