I am looking for a word or two that elegantly expresses the idea that the projects I did were a valuable learning experience. Here's the sentence: While I was doing my bachelor's I was a part of some .......... projects.
See heuristic. It means involving or serving as an aid to learning, discovery, or problem-solving.
Another similar word is didactic, which means that something designed or intended to teach people something.
Also, for catchy phrase try "propitious projects."
Propitious means likely to result in success, or showing signs of success. It also means favorably disposed, or tending to favor. The projects you did turned out to be propitious because you learned a lot from them.
Keep it simple unless you're looking to impress people with your amazing vocabulary!
- While I was doing my bachelor's I was a part of some stimulating projects.
- While I was doing my bachelor's I was a part of some unforgettable projects.
- While I was doing my bachelor's I was a part of some exciting projects.
- While I was doing my bachelor's I wasa part of some memorable projects.
I sometimes use the word pedagogic on sites like these. It just means "relating to teaching."
So, say there is a programming QA on stackoverflow. You might find yourself saying things like ...
"Although you wouldn't do it that way in a typical project, that answer has excellent pedagogic value."
"Even though it's a duplicate, this question has good pedagogic value."
"The arcane detail you mention is important, but it's better to stick to the main issue for pedagogic reasons."
So, it can be quite useful.
(As others have said, "valuable learning experience" fits perfectly for the exact example you give, and you need look no further.)