  We review recent applications of the integrable discrete Hirota dynamics
(Y-system) in the context of calculation of the planar AdS/CFT spectrum. We
start from the description of solution of Hirota equations by the Backlund
method where the requirement of analyticity results in the nested Bethe ansatz
equations. Then we discuss applications of the Hirota dynamics for the analysis
of the asymptotic limit of long operators in the AdS/CFT Y-system.
