DP(Dynamic Programming) is such a beautiful technique .It took a while for me to grasp it . There are many applications in real world systems as well. Eg Duck DB's join order optimizer is built on https://15721.courses.cs.cmu.edu/spring2020/papers/20-optimi... .
https://github.com/duckdb/duckdb/blob/61f07c3221e01674d8fe40...