F-theory has emerged as a promising framework for engineering supersymmetric Grand Unified Theories (GUTs) in string theory. In this talk, we will describe recent progress in this field with an emphasis on connecting "local" and "global" approaches. The "local" approach, which we shall review, focuses on only that part of the internal geometry probed by particle physics experiments. This is the analog of bottom-up phenomenology and has led to a variety of "local" models that can reproduce several important qualitative features of the Standard Model. The "global" approach, however, is the analog of top-down phenomenology and focuses only on compact, globally consistent string backgrounds. We will describe both approaches in detail and how merging them tightly constrains the particle physics models that can arise from F-theory models in general.