Massive stars are fundamental drivers of galactic evolution, exerting powerful feedback on their surroundings and shaping the ecology of their host galaxies. Over the past decade, high-resolution observations and state-of-the-art theoretical modeling have significantly advanced our understanding of their formation processes. In this poster, I will present our recent theoretical and observational studies of massive star formation in Galactic and lower-metallicity environments. Specifically, I will discuss, from both theoretical and observational perspectives, (1) how feedback models self-regulate accretion onto massive protostars, (2) the latest disk studies that shed light on accretion and dust/chemistry in hot environments, and (3)key findings on massive protostars in the Magellanic Clouds, highlighting the potential diversity of star formation processes across different galactic contexts.
