QCD aspects of exclusive heavy-hadron decays will be discussed with an emphasis on the perturbative factorization properties for the resulting hadronic matrix elements in the heavy quark expansion and on the systematic discussions of the distinct dynamical mechanisms governing the flavor-changing form factors beyond the leading-power approximation. Phenomenological implications of the technical improvements for evaluating the heavy hadron decay amplitudes will be further elaborated with a number of interesting exclusive processes accessible at the LHCb and Belle II experiments.