Modular representation theory studies representations of a finite group and other algebraic structures such as Lie algebras over a field of positive characteristic. Classifying modular representation up to direct sums – as the classical theory does for complex representations – is often a hopeless task even for such a tiny group as Z/3 x Z/3.  I’ll discuss a geometric approach to understanding this wild territory starting with Quillen’s classical work on group cohomology and leading to the applications of the ideas in tensor triangular geometry of P. Balmer in the context of modular representation theory.