[nikonyrh]

I suppose all SW engineers have experience with data structures, when you are choosing whether to store the data into a dictionary, array or linked list. It is a bit more stretch to ask whether you've implemented a database before or not. On a more advanced level you'd dive into topics such as copy-on-write and software transactional memory (hobby-wise I come from Clojure background).

As an example, do you know how git works?

Edit: Oh an other great example of data structures is torrent files (and magnet links). Hint: https://en.wikipedia.org/wiki/Merkle_tree