The controlled use of electronic excitations in materials has led to important technological advancements, such as the design of cutting-edge optoelectronic devices and the development of energy-efficient materials. Understanding electronic excitations is crucial for unlocking the full potential of materials, and ab initio methods offer insight into these quantum-level processes without requiring extensive experimental input. However, as materials become more complex, with thousands or even millions of atoms, and real-world conditions come into play, accurately simulating these systems becomes a significant computational challenge. Macroscopic phenomena like optical absorption, luminescence, electrical conductivity, and other bulk or surface material properties can't be fully captured by microscale models alone due to the complex interactions across larger length and time scales. As a result, studying electronic excitations in complex disordered systems remains a challenge for ab initio methods.