Epithelial tissues are cohesive sheets of cells that perform a variety of mechanical functions which include maintaining a cohesive barrier or developing 3D shapes, while undergoing stretches over a wide range of magnitudes and loading rates. To perform these functions, epithelial tissues rely on a hierarchical organization, which spans molecules, cytoskeletal networks, adhesion complexes and junctional networks up to the tissue scale. While the molecular understanding and ability to manipulate cytoskeletal components within cells is rapidly increasing, how these components integrate to control tissue mechanics is far less understood. In this talk, I will describe a theoretical and numerical framework that allows one to upscale subcellular dynamics to epithelial mechanics. Starting from a non-euclidean hydrodynamic description of the subcellular physics, the resulting framework, akin to vertex models, is transparent, in that the microscopic origin of every vertex force contribution is clear, and modular by design, such that inclusion of any additional physics is straightforward. We use this model to simulate and capture a wide variety of seemingly disconnected epithelial phenomenologies.