In this thesis, we begin with a personal inquiry into “How can I make a sustainable impact?” and return to the moment when we discovered sustainability. Drawing on our personal background and reflection, we are curious to know "What competences are required for a career in sustainability?" To answer this question, we build our research upon the concept of Action Competence which articulates the necessary abilities to engage in solving sustainability issues. The action-oriented competences consist of motivation, skill and knowledge, as well as confidence, which collectively enable individuals to take responsible actions. Based on this concept, we interview alumni of the Master's Programme in Sustainable Management of Uppsala University, Campus Gotland, and identify the aspects required in a sustainable career. The aim of the thesis is to provide a comprehensive framework for understanding the desirable characteristics of sustainability professionals. Our research provided empirical evidence supporting the concept of Action Competence, in which the individuals under study demonstrated a high level of motivation, relevant knowledge and skills, and moderate confidence. Based on this theory, we introduce "The Egg Model," comprising the elements of hope, curiosity, and community. These additional elements contribute to a holistic understanding of the essential competences for a successful career in sustainability. The implications of our research aim to make meaningful contributions to the field of sustainability management. Individuals, higher education institutions, and companies can enhance their competences to a sustainable future.