Jet substructure is a versatile tool that has been widely used to tag different types of jets, enabling new searches and measurements at the LHC. While its use for tagging has been broadly studied, it is also sensitive to QCD across a wide range of scales, and can be used to study parton showers and hadronization. This talk will discuss experimental challenges of jet reconstruction and explore how substructure measurements enable new tests of QCD. The talk will conclude with future applications and directions for this work at the LHC and beyond.