Modeling galactic nuclei fueling and feedback in a full cosmological context is a crucial step towards understanding the nature of black hole-galaxy co-evolution. Despite much recent progress, cosmological hydrodynamic simulations have been traditionally limited by resolution, interstellar medium physics, and the treatment of black hole physics. In this talk, I will present results from the Feedback In Realistic Environments (FIRE) project, modeling stellar feedback by supernovae, stellar winds, and radiation on the scale of star-forming regions and black hole growth using a gravitational torque-based prescription tied to the properties of galactic nuclei. By resolving the inner 100 pc of galaxies, I will show that bursty stellar feedback regulates the gas reservoir in galactic nuclei and can severely limit early black hole growth, which has important implications for black hole-galaxy scaling relations, AGN demographics and time variability, the formation of early quasars, and massive black hole mergers. I will then present ongoing work on cosmological hyper-refinement simulations that for the first time resolve AGN fueling and feedback in z=2 massive galaxies on ~1 pc scales in a multi-phase interstellar medium.
