An example (not the best one maybe but I'm not the right guy to come up with good examples immediately) from a year ago:
We have to integrate company M and W (one is a marketplace the other one is a big store, think Walmart or something).
Company W mostly uses software similar to SAP-whatever and have a small team resposible for building 'helper' services in place where SAP can't do the job.
Company W can't communicate with M in any other way except through your generic http API they provide.
So every now and then M has to send a request to W and W has to prepare a pretty large XML response. (obviously the data is split in some way and we are not talking about tens of GBs but even so W has has to fetch the data from more than one data source, process it and send it)
In some cases you can simply have a cache\a view\whatever for this (so you only have to fetch prepared data) but in some cases you can not.
PS: this is if we are talking about HTTP communication. Or maybe some real-time communication where you can't really respond with "hey, we are getting your data prepared so just wait for a bit and re-request it with this nice jobID at a later time"
Well, for that use case, it would be typical in my industry for party A to send a callback URL to party B, so that B can POST the required information back to A after doing the multi-step processing. It's not really a done thing to make a synchronous HTTP request and wait say a minute or more for the response. Maybe that's just different expectations in different industries, though.
We have to integrate company M and W (one is a marketplace the other one is a big store, think Walmart or something).
Company W mostly uses software similar to SAP-whatever and have a small team resposible for building 'helper' services in place where SAP can't do the job.
Company W can't communicate with M in any other way except through your generic http API they provide.
So every now and then M has to send a request to W and W has to prepare a pretty large XML response. (obviously the data is split in some way and we are not talking about tens of GBs but even so W has has to fetch the data from more than one data source, process it and send it)
In some cases you can simply have a cache\a view\whatever for this (so you only have to fetch prepared data) but in some cases you can not.
PS: this is if we are talking about HTTP communication. Or maybe some real-time communication where you can't really respond with "hey, we are getting your data prepared so just wait for a bit and re-request it with this nice jobID at a later time"