Interfaces play a vital role in governing the behaviour of many complex systems in computational mechanics, particularly in soft and heterogeneous materials where transport processes and mechanical deformation interact across multiple spatial and temporal scales [1]. In such systems, evolving interfaces regulate load transfer, control transport pathways, and strongly influence macroscopic response, making them a critical focus for predictive modelling. However, accurately capturing interfacial behaviour remains challenging due to the combined effects of geometric complexity, strong multiphysics coupling, and multiscale structure. Conventional numerical strategies often fail to rigorously address these features simultaneously, either due to limitations in geometric flexibility, insufficient conservation at the discrete level, or reduced robustness under strongly coupled conditions. This contribution presents a geometry-aware, conservation-preserving computational framework to analyse interface-dominated multiphysics behaviour in soft and heterogeneous systems. The approach combines element-based finite volume discretisation with modular coupling strategies to robustly capture interactions between deformation mechanisms and transport processes on irregular geometries [2]. By enforcing local conservation at the discrete level, the framework remains stable under large gradients, evolving interfaces, and strong coupling. Dynamic contact and separation between interacting constituents are represented via robust interface formulations, enabling smooth transitions between interaction regimes and accommodating deformation-driven changes in local transport routes [3]. Representative numerical studies demonstrate the ability of the framework to resolve hydrodynamic and structural responses on complex geometries while maintaining robustness and scalability. The results highlight the versatility of element-based finite volume formulations as a computational foundation for multiscale, coupled transport processes, enabling next-generation bio-chemo-mechanical modelling of compliant and intricate interfacial systems.