Optimization. In particular, he is specialized in the design of mathematical models and methods (such as integer programming and branch-and-price) and metaheuristics (in particular, local search based meta-heuristics) for problems arising in complex systems. He has been involved with the design and implementation of software (OOP) related to decomposition methods which combine linear and integer programming models, problem-specific algorithms, and metaheuristics. The main applications where he have been working are in telecommunications, cutting and packing, and kidney exchange programs.