Me: Ok, we'll implement that message tech. But since the clients are servers in that architecture and can't speak IPv6 we've to use a dedicated VPN so the endpoint is able to connect to the servers (clients). Since we have limited network resources we should use VPN cert-encryption and send the actual data plain to save at least some overhead.

Boss: Ok! Let's do it!

Next day.

Boss: Hey! I talked to a guy from that message tech. Their encryption is certified. We should use that instead and get rid of the VPN to save the overhead!

Me: *unable to say a word*

What in "VPN in that architecture is mandatory" is unclear?

Well, I assume we'll kill the architecture then... Fun Time!