Partially ordered sets (posets) are important objects in combinatorics (with many connections to https://gilkalai.wordpress.com/2019/02/05/extremal-combinatorics-v-posets/basic connections to extremal combinatorics and to algebraic combinatorics) and also in other areas of mathematics. They are also related to sorting and to other questions in the theory of computing. I am asking for a list of open questions and conjectures about posets.