The primary function of a systems architect is to design and oversee the implementation of complex information systems within an organization. They bridge the gap between business requirements and IT solutions by evaluating existing systems, identifying areas for improvement, and recommending appropriate technologies. Systems architects focus on aligning technology with business goals, ensuring scalability, security, and performance. Additionally, they create architectural models and documentation, leading cross-functional teams in system integrations and project implementations while adhering to industry standards and practices.