There have been quite a few of these in the past. Some of the 2018 problems (e.g. day 21 [1]) required quite a lot of reverse engineering of programs in a cust

There have been quite a few of these in the past. Some of the 2018 problems (e.g. day 21 [1]) required quite a lot of reverse engineering of programs in a custom instruction set. [1] https://adventofcode.com/2018/day/21 https://adventofcode.com/2018/day/21