Symplectic duality is an equivalence between holomorphic Fukaya categories, called categories O, associated to pairs of holomorphic symplectic manifolds. All known dual pairs arise as Higgs and Coulomb branches of the moduli spaces of vacua in 3d N=4 theories and, together with Bullimore, Dimofte, and Gaiotto, I showed that category O could be identified with a certain category of boundary conditions for these theories. In recent work Braverman-Finkelberg-Nakajima have given a rigorous mathematical definition of the Coulomb branch. I will explain how one can incorporate boundary conditions and interfaces into this construction. In particular one can show that the BFN construction is functorial with respect to holomorphic Lagrangian correspondences. The case when the Lagrangian is a cotangent fiber is joint with Joel Kamnitzer and Alex Weekes.