  An energetic parton travelling through a quark-gluon plasma loses energy via
occasional hard scatterings and frequent softer interactions. Whether or not
these interactions admit a perturbative description, the effect of the soft
interactions can be factorized and encoded in a small number of transport
coefficients. In this work, we present a hard-soft factorized parton energy
loss model which combines a stochastic description of soft interactions and
rate-based modelling of hard scatterings. We introduce a scale to estimate the
regime of validity of the stochastic description, allowing for a better
understanding of the model's applicability at small and large coupling. We
study the energy and fermion-number cascade of energetic partons as an
application of the model.
