Test suite optimization is a crucial topic in software testing which was recently boosted by the contributions of constraint programming and search-based algorithms. The increased complexity of testing procedures and the combinatorial nature of the underlying testing problems, namely (multi-criteria) test suite reduction, prioritization and scheduling requires the usage of advanced techniques which have been developed in other contexts. In this talk, I will review some of these advances and their application to real-world testing problems that we address in Certus, the Norwegian research-based innovation centre dedicated to Software Validation and Verification.