Abstract: There is now an amalgam of observational evidence that massive stars undergo enhanced and/or eruptive mass-loss in their final years before explosion. In this talk, I will discuss how multi-wavelength observations of type II supernovae both before and after explosion can be utilized to probe the late-stage evolution of massive stars from months-to-millennia before core collapse. I will highlight ongoing observational efforts within the Zwicky Transient Facility (ZTF) to autonomously identify and trigger multi-wavelength follow-up within days of explosion as well as discuss the new synthesis between ZTF and LSST that is being used for young supernova discovery. Additionally, I will describe recent results from panchromatic studies of type II supernovae at years-to-decades post-explosion and how such observing campaigns, coupled with state-of-the-art radiative transfer modeling, can quantify shock physics and the unknown late-stage mass-loss rates of red supergiant stars.