Real world example: uploading product, inventory and pricing data to ChannelAdvisor for processing and then republishing out to multiple e-commerce platforms (Amazon, Jet, Rakuten, etc). CA is a big complex powerful system, and my team was uploading FTP files every few minutes. We had the same kind of issues that E2E email delivery and receipt testing would be important for. In our case, we needed to know more about how many of those files were being read, injested, etc. There were dependent processes that could only be triggered if the data had made it into the system. We relied on process scheduling intervals to get close, but knowing more about the state of the ftp pickup itself could’ve improved yields to what we were trying to do.