Many REST services implement sending files, documents etc. by having a body with multipart/form-data. There are many questions on the forum about this, e.g. here, here and here. Unfortunately, the OutSystems Platform lacks native support for this, leading to workarounds like this Forge Component or "manually" modifying the request data in the OnBeforeRequest, which leads to things ugly code like this:
(Yeah, that's mine :).)
So it would be a great addition to the Platform if it had native support for multipart/form-data for REST services, at the very least for consuming them. That would make our lives just a tad bit easier!