This document discusses an Enterprise Service Bus (ESB) and promotes UNCAL ESB. It begins with an introduction to ESBs, explaining how they can reduce complexity by enabling different applications, systems, databases, and devices to connect and communicate through a centralized interface. The document then highlights benefits of ESBs like reduced maintenance costs, improved agility, and centralized monitoring. It promotes UNCAL ESB as the first ESB developed in Indonesia and notes features like enabling any system or message type to connect, faster development through templates and drag-and-drop tools, high performance with millisecond response times, and satisfied customers. It encourages starting a digital transformation journey using UNCAL ESB.