Maryna Viazovska is a Ukrainian mathematician and Chair of Number Theory at the École Polytechnique Fédérale de Lausanne (EPFL). She is best known for solving the sphere-packing problem in dimension eight, proving that the E8 lattice gives the densest possible packing of spheres — a problem that had remained open for over a century. Shortly afterward, with collaborators, she extended the result to dimension 24 using the Leech lattice. Her method, built on a strikingly elegant construction of modular and quasimodular forms as 'magic functions,' surprised the community with its economy and has since influenced areas from coding theory to Fourier interpolation and the theory of universal optimality. For this work she became the second woman to receive the Fields Medal, in 2022, and she also won the SASTRA Ramanujan Prize and the Salem Prize. Her work is theoretical, with no patents or industry ties, though sphere packing connects directly to error-correcting codes and signal processing. She serves as an academic anchor for outreach to number-theory, optimization, and coding-theory communities in research and engineering.