  We analyze intersecting surface defects inserted in interacting
four-dimensional N = 2 supersymmetric quantum field theories. We employ the
realization of a class of such systems as the infrared fixed points of
renormalization group flows from larger theories, triggered by perturbed
Seiberg-Witten monopole-like configurations, to compute their partition
functions. These results are cast into the form of a partition function of
4d/2d/0d coupled systems. Our computations provide concrete expressions for the
instanton partition function in the presence of intersecting defects and we
study the corresponding ADHM model.
