Explore theoretical challenges in string phenomenology through a 37-minute conference talk by Manki Kim from the Center for Theoretical Physics. Delivered as part of the Spacetime and String Theory conference at the Kavli Institute for Theoretical Physics, this presentation delves into cutting-edge research bridging the gap between infrared and ultraviolet perspectives in string theory. Gain insights into recent advancements in non-perturbative string theory, stringy constraints on effective field theory, and the connections between gravitational path integrals, higher topologies, and entanglement across energy scales. Discover how this talk contributes to a new synthesis in the field, incorporating quantum information, string compactification techniques, and holographic dualities beyond anti-de Sitter space.