The objectives of the study were to identify the relationship between the personal traits and sustainable competence development of library professionals, explore trending practices for the development of the personal and professional competencies of librarians, and find out the challenges affecting the development of modern skills in librarians. The authors applied the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines as a research methodology. Thirty-five peer-reviewed articles were selected to conduct the systematic literature review. The results revealed that there is a strong positive correlation between personal traits and the professional development of librarians. The trending practices for the development of personal and professional skills included expert use of IT, continuous training sessions, teamwork, usage of social media forums, and a customer-oriented approach. The results also showed that old curricula, leadership problems, economic issues, and lack of personal interest were barriers to the development of modern skills in librarians relating to the implementation of value-added services in the networked world. The study contributes theoretically by adding valuable knowledge to the existing literature. It outlines practical implications to help devise strategies for capacity building among librarians related to the implementation of user-centered services in libraries.