Explore orbital evolution in binary systems through this conference talk from the Building Bridges conference at KITP. Delve into the complexities of circumbinary gas, its evolution, and influence on embedded binaries. Examine observational signatures, numerical modeling techniques, and the similarities between massive black hole binaries and stellar binaries. Gain insights from experts Selma De Mink and Sophie Schroder as they discuss topics such as common envelopes, discs, post-HP binaries, gas vs. dust dynamics, and the importance of binary evolution in understanding these systems. Learn about mass loss, merger rates, stellar mergers, and the effects of jets and winds on orbital evolution. Discover simulation results, parameter space exploration, and key questions in the field of binary system evolution.