Ex employee of Meditech Minnesota here. Magic and its variants were pretty interesting to work with. The only reason I left was what you said, about experience

Ex employee of Meditech Minnesota here. Magic and its variants were pretty interesting to work with. The only reason I left was what you said, about experience being crippled by not having any standard languages under your belt working there. Proprietary language concerns aside, it was fascinating using the tech there. Backend was Magic, as described by you and others. Direct B-Tree manipulation meant I didn't learn about the relational model but learned to reason about performance and indexing very directly. The front-end language was what I found particularly fascinating though. It was concatenative, along the lines of Forth, and had some fairly powerful functional constructs, like a multi-part IF/Case where the first true expression would be returned to the outer scope. Stuff was stringly-typed everywhere I remember, and with little to no safety on anything - I once found a bug where adding 1 to a list caused the ending delimiter to become something else and the list became unbounded in memory. Awesome languages to write in, terrible to debug.