  We discuss the computation of correlation functions in holographic RG flows.
The method utilizes a recently developed Hamiltonian version of holographic
renormalization and it is more efficient than previous methods. A significant
simplification concerns the treatment of infinities: instead of performing a
general analysis of counterterms, we develop a method where only the
contribution of counterterms to any given correlator needs to be computed. For
instance, the computation of renormalized 2-point functions requires only an
analysis at the linearized level. We illustrate the method by discussing flat
and AdS-sliced domain walls. In particular, we discuss correlation functions of
the Janus solution, a recently discovered non-supersymmetric but stable
AdS-sliced domain wall.
