Core collapse supernovae (SNe), the catastrophic explosions of massive stars, play a central role in shaping the observable universe. However, explaining the observed diversity of these events remains a key unsolved problem. The effects of mass, metallicity, binarity and rotation on the evolution and subsequent explosions of massive stars are not well understood. We use observtions of large samples, recently collected through novel surveys such as the Palomar Transient Factory (PTF) to unlock new observational insights into this problem. By comparing the light curve shapes of numerous SNe we find three distinct sub-types of H-rich events, pointing towards different mechanisms at work and hinting at the effects of binarity. PTF has allowed us to discover an unprecedented number of SNe in extremely metal poor environments, elucidating the significance of metallicity in creating different types of stripped SN progenitors. Early discovery and rapid followup enable us to observe SNe as soon as hours after the explosion, allowing us to constrain additional properties of SN progenitors, including their radius and pre-explosion structure. As more data is gathered, we are finally approaching a more complete understanding of the mysteries behind these fascinating events.