ADP is a leading global provider of business outsourcing solutions, specializing in areas such as human resources, payroll, and benefits, with a client base that includes over 80% of Fortune 500 companies. The company aims to enhance client experience through a new service portal that consolidates various applications into a single entry point for improved efficiency and collaboration. By leveraging technologies like MongoDB and Node.js, ADP seeks to streamline tax services and ensure high-quality service delivery.