Right-angled Coxeter groups form an extremely accessible class of objects in geometric group theory. They are defined by simple presentations: they are generated by involutions, with the only additional relations requiring certain pairs of generators to commute. Despite this elementary definition, they display an extraordinary range of geometric behaviors. In this talk, I will survey the progress in understanding their large-scale geometry, focusing on questions about quasi-isometry. In particular, I will talk about recent joint work with Cashen, Schreve and Stark exhibiting infinitely many quasi-isometry classes of right-angled Coxeter groups with Pontryagin sphere boundary.