The advent and development of large-scale time domain surveys are revealing the existence of a large and diverse zoo of transients; common transients that can be used as tools to constrain GR or cosmological parameters, and rare & exotic transients that are observed for the first time. The origin of the transients is often unknown, but linked to stellar systems and interactions. In this talk I will show novel channels to induce stellar interactions and subsequent transients - in electromagnetic radiation as well as gravitational waves. Amongst others I will discuss how triple stars can evolve differently from binary stars, and show their potential as transient progenitors. While triple star systems are common, our understanding of their evolution has lagged behind compared to single and binary stars. I will conclude with revealing a new primary channel of binary evolution towards supernova type Ia events.