Lightweight constructions can no longer be achieved solely through material substitution. To stay competitive, design parameters and manufacturing technologies should be taken into consideration as well. The integrated process of Deep Drawing-Back Injection Molding (DDBIM) is such an advanced process in which the sheet metal blank is first deformed by tool movement and then calibrated to the shape of the cavity using polymer melt pressure during the injection process. Therefore, the traditional processes of sheet metal forming, and injection molding are combined into one step operation, thus reducing the process steps and required machinery. Even though the process has its own challenges, the best combination of weight, performance, cost, and quality can be achieved by defining a multi-objective optimization problem with respect to the influencing design parameters. This study aims to optimize the various parameters of the sheet metal-polymer structure using Taguchi-based Grey optimization. A system of orthogonal arrays is used as the design of experiment (DOE) in order to evenly distribute the design variables in the design space. Moreover, S/N ratio studies are employed to determine the parameters that have a higher impact on the objective functions. The profiles suggested by DOE are then simulated using ABAQUS, and the objective functions are reported for the optimization step. Finally, the results of the simulation step along with the corresponding design variables are used for the multi-objective optimization process. The optimization results suggest a remarkable improvement in the objective functions. The suggested optimal profile not only held high values of energy, stiffness, and maximum load, but also resulted in 11% and 14% reduction in mass and cost, respectively.