I'm not sure what the curriculum looks like for the "business informatics" at your school, but if it's anything like what a similar "business CS" program offered at my college was it is mostly admin/management stuff or setting up and maintaining enterprise software (Cisco routers, using Microsoft products, ect). I had a friend who took a 300-level (Junior) class as an elective and they introduced Vim/Emacs halfway through and tested on it...we were both amazed at that level many of them hadn't even written much code, worked on a large code-base, or had a grasp on any programming paradigms/design patterns yet were getting a degree in a computer field in less than a year. I guess it goes to show how different levels of abstraction can be applied to CS to get a job done (ie. they didn't need to know how any of the tools worked internally...just how to use them to accomplish a job).

> Will chosing the "business informatics" major make me drastically less employable in software engineering positions, even if I have a good portfolio of personal projects?

Drastically? Probably not, especially if you have some projects under your belt to demonstrate your skills. If your goal is to be a "software engineer" though, I think you're better off getting a CS degree because it directly feeds into a software career.

> Will I miss out on a lot of core concepts in the theoretical & technical Computer Science courses, which will make me less proficient in programming later on?

Of course you will miss out on some things. There is a reason these are 2 different programs at your school because they are aiming at teaching 2 different things. CS dives into theoretical components such as OS design, programming paradigms and design, algorithms, ect. Now you can learn all these on your own of course, but I find it far more difficult especially at a higher level of understanding. "business informatics" (as I understand it), is about putting software in place which is going to aid business in some way or possibly train you to be in some sort of "software management" position.

Just my 2 cents though.