Smorg,
There are a number of players in the ETL (or in some cases ELT) field, although some of them have been acquired by larger companies, it’s still the same basic technology. The most common use cases are moving data from a transactional production system to a data warehouse platform or an archival medium. These tend to run on a periodic schedule and consist primarily of mapping from the transactional system to the other platform coupled with simple conditioning and transforms (i.e. possibly transforming relational structures to XML hierarchies).
Data conversions are a different ballgame. If I were so motivated, I could write a book about the kinds of problems you run into with conversions, but most of them have to do with data pollution. I don’t believe there’s any tool that could be built to handle all the wrinkles that crop up in a system that’s been in production for 20 years or so. Humans can be very creative in finding ways to make applications bend to their will irrespective of all the edits and error conditions that have been anticipated by the IT staff.
I’ll admit, I’ve not looked into Mulesoft and maybe I shouldn’t be so skeptical, But after 30 years in IT, most of it devoted to application development with associated conversions I find it hard to conceive that there’s new silver bullet that can slay this monster. None of the older silver bullets ever killed it. But, technology marches on, maybe . . . .