D-branes at Calabi-Yau singularities provide a bridge between algebraic geometry and quantum field theories. The Calabi-Yau geometry determines the quantum field theory on the D-brane worldvolume. Many interesting properties of the quantum field theory such as anomalies and beta functions can be translated into statements about the Calabi- Yau geometry. One of my research goals is to expand this dictionary and create effective methods to determine the quantum field theory associated to a given Calabi-Yau singularity.