This work is focused on the optimization of the geometrical characteristics of a recuperator developed for aero engine applications, taking into consideration the aero engine geometrical constraints and limitations, in order to achieve feasible and implementable recuperator designs. For this reason, dedicated numerical surrogate tools were developed through which the effect of major geometrical features such as recuperator diameter, length, tubes arrangement and alignment could be directly included in order to assess their effect to recuperator operational performance characteristics such as recuperator effectiveness and inner/outer pressure losses. A large part of these activities was focused on the development of a nonlinear surrogate model incorporating the major geometrical features of the recuperator. In this tool, high-fidelity correlations regarding pressure losses and heat transfer, derived through experimental measurements and detailed CFD computations, were incorporated. Based on this model the recuperator performance was optimized using the simulated annealing algorithm resulting in the identification of recuperator design which can combine operational superiority with feasibility and implementation potential.