Hiring a Manager/Employee Self-Service developer is crucial for streamlining HR processes. They can develop a centralized platform where employees can access services such as leave applications or payroll information. This not only empowers employees by giving them direct control over their personal data, but also reduces the administrative burden on HR, leading to increased efficiency. The developer can also integrate AI and machine learning features to automate routine tasks, improving overall productivity. They can ensure data security and compliance, providing a safe, user-friendly environment for employees to manage their information.