We present the first-principle derivation of a weak-strong duality between
the fishnet theory in four dimensions and a discretised string-like model
living in five dimensions. At strong coupling, the dual description becomes
classical and we demonstrate explicitly the classical integrability of the
model. We test our results by reproducing the strong coupling limit of the
4-point correlator computed before non-perturbatively from the conformal
partial wave expansion. Due to the extreme simplicity of our model, it
could provide an ideal playground for AdS/CFT with no supersymmetry.
Furthermore, since the fishnet model and N = 4 SYM theory are continuously
linked our consideration could shed light on the derivation of AdS/CFT for
N = 4 SYM too.
