How do we import and use 3rd party libraries. For example jar files in java. More ideally we have maven pom files.
I think you can do it by creating an extension in Integration Studio. I've found this documentation article talking about how to create extensions that can be useful to you :)
I've found that just importing external libraries usually doesn't lead to a good experience. You end up having to do a ton of "ToObject" calls back and forth, because you are trying to send data back and forth to it, plus you need to understand how to use the library. Instead, I like to write an extension that encapsulates the libraries and summarizes their functionality into an easy-to-use, OutSystems-like experience, where the inputs/outputs make sense to someone who only is using OutSystems.