[jhh]

I was also surprised by that but there may be some slightly unusual background reason for that that simply doesn't get mentioned. Superficially it sounds like the author should just... do the HTTP request? Since they're waiting for the response anyway

[physicsguy]

I'm not sure the exact idea here because they said something about retrieving PDF and JSON data, but a big reason for not doing this is normally that some calculation or whatever takes a lot longer than you want a HTTP request to take. So you effectively push the work off, and then the user comes back at a later time and something has been processed and they can see the result.