The clustered nature of star formation leaves a long-term imprint on galaxies, stars, and planets. At young ages, stellar clustering subdivides galaxies into individual building blocks undergoing vigorous, feedback-driven life cycles that vary with the galactic environment. These units structure the interstellar medium spatially, dynamically and chemically, and collectively define how galaxies form stars. At old ages, the relics of clustered star formation persist as ancient globular clusters, which hold a wealth of information allowing us to reconstruct the assembly histories of galaxies, culminating in the reconstruction of the Milky Way’s merger tree. Towards smaller scales, stellar clustering has a measurable impact on the evolution of protoplanetary discs, the architectures of planetary systems, and the properties of planets themselves. I will discuss how this web of physical processes across a hierarchy of scales defines the cosmic ecosystem that we live in, and demonstrate that stellar clustering is at its focal point.