In response to the rapid and dynamic changes in the economic environment, companies must improve their processes to maintain competitiveness. This includes enhancing their intellectual capital, with particular emphasis on effective onboarding processes, which play a crucial role in integrating new employees and retaining talent. This enhances the value of the organization’s intellectual capital and emphasizes onboarding—the training and integration of new employees—whose proper functioning impacts staff retention. Drawing on both Hungarian and predominantly foreign literature, we highlight onboarding processes and examine their implementation in Hungarian companies of various sizes. The research employed a mixed-method approach, combining semi-structured interviews and questionnaires. In-depth interviews were conducted with HR leaders from 13 Hungarian organizations to explore the existence of mentoring programs. Additionally, 161 employees across Hungary completed questionnaires, which examined their perspectives on onboarding processes and the relationship between mentoring programs and company size. We analyzed the data using chi-square tests to assess the strength of these relationships. While all large companies in our sample had formal mentoring programs, smaller companies displayed more variability, with some relying on informal or ad-hoc onboarding processes. Based on these results, we identified several key areas for improvement in onboarding processes. These include enhancing the structure of feedback interviews, ensuring more comprehensive communication channels, and strengthening mentoring programs across companies of all sizes. By addressing these gaps, companies can improve employee retention, engagement, and overall integration during the onboarding process, contributing to a more stable and motivated workforce.