Some recent results in massive binary evolution

The evolution of massive stellar binaries plays a key role in the formation of a range of transients: gravitational-wave sources, gamma ray bursts, some supernovae, luminous red novae, etc. Unfortunately, a variety of key steps in the evolutionary process are poorly understood. I will discuss some recent theoretical work on a range of processes, from common envelope physics to wind-driven mass loss, and show the impact of new observational constraints.