Hadronic reactions at high energies can reach a kinematical domain where gluon densities become non-perturbatively large even at short-distance scales where the QCD coupling is weak. A convenient effective theory of QCD in this regime is provided by the color glass condensate, which describes the nonlinear small x degrees of freedom in a hadron or nucleus as a classical color field. An ideal way to study these dense color fields is to probe them with simple dilute probes, such as in forward particle production in proton-nucleus collisions or deep inelastic scattering. In this talk I will present recent progress on extending the color glass condensate description of these two processes beyond leading order, which is essential for reliable phenomenological applications.