Abstract
Our current picture of the subatomic world is remarkably successful as well as incomplete. I will elaborate on the necessity to go beyond the Standard Model, but also and foremost on the numerous theoretical and experimental constraints that any of its extensions has to confront. Among the many open questions in particle physics phenomenology, a few of them, commonly known as “fine-tuning problems”, seem to challenge our intuition the most. I will review the main approaches to these puzzles and their implications.