Jets in the vacuum correspond to multi-parton configurations that form via a branching processsensitive to the soft and collinear divergences of QCD. In heavy-ion collisions, energy lossprocesses that are stimulated via interactions with the medium, affect jet observables in a profoundway. Jet fragmentation factorizes into a three-stage process, involving vacuum-like emissionsabove the medium scale, induced emissions enhanced by the medium length and, finally, long-distance vacuum-like fragmentation. This formalism leads to a novel, non-linear resummation ofjet energy loss. In this talk we present new results on the combined effects of small-Rresummationand energy loss to compute theR-dependent jet spectrum in heavy-ion collisions.