Modern SDN solutions for optical transport networks are typically designed for single-vendor environments, where optical domains operate as independent entities in a fully aggregated deployment model. Although SDN controllers abstract network resources and expose them to higher level through a north-bound interface (NBI), internal mechanisms for resource management, monitoring, and control remain proprietary. Disaggregated optical networking offers an alternative approach by integrating open and commercially available components, devices, and subsystems to build optical systems. By embracing disaggregation, operators gain greater flexibility in upgrading and migrating components without being tied to a single vendor. However, this model requires careful trade-offs between performance, vendor support, and cost efficiency.