One of the most important families of vertex algebras are affine vertex algebras and their associated W-algebras, which are connected to various aspects of geometry and physics. The structure and representation theory of a given $\mathcal{W}$-algebra depends largely on the type of nilpotent element used in the construction, and in most cases results cannot be obtained using a direct approach. In this talk I will present some recent results about duality and representation theory of certain subregular W-algebras at integer levels.