Antifragility has recently emerged as a design principle changes during their operations. In this "New Ideas"paper we intend to support the vision that an effective application of this principle requires a clear understanding of the implications of its adoption and of its relationships with other approaches sharing a similar objective. To this end, we argue that a proper conceptual characterization of antifragility can be achieved through its inclusion within the consolidated dependability taxonomy. From this conceptual characterization we identify open architectural challenges towards the definition of a reference model for antifragile systems. © 2023 IEEE.