An improved understanding of the lifecycle of massive stars benefits every subfield in astrophysics. Through their ionizing radiation, powerful stellar winds, nucleosynthesis, and deaths as supernova (SN) explosions, massive stars give birth to black holes and neutron stars, while stoking the dynamical and chemical evolution of the universe. Although the study of massive stars is one of the oldest subfields in astronomy, the recent advent of wide-field time-domain surveys has launched an upheaval in field of stellar evolution. In this talk I will highlight on-going efforts to constrain the evolution and ultimate fate of massive stars, using observations of both transient phenomena and time-domain studies of resolved massive star populations in Local Group galaxies. Finally, I will give a status update on the KMTNet Supernova Project (KSP). KSP is a survey run with ~25% of the time on the Korean Microlensing Telescope Network (KMTNet)--a network of three telescopes in Chile, South Africa, and Australia--- the goal of which is the study of rapid extragalactic transients and early SN light curves.