OR-Tools is an open-source software suite for solving combinatorial optimization problems. These optimization problems have a very large set of possible solutions, and tools like OR-Tools are quite helpful in seeking the best solution. You can model the problem in any one of the supported languages — Python, Java, C# or C++ — and choose the solvers from several supported open-source or commercial solvers. We've successfully used OR-Tools in multiple optimization projects with integer and mixed-integer programming.