A Custom CMS developer designs and builds personalized content management systems (CMS) tailored to fit specific business requirements. They analyze client needs, create system specifications, and design the software architecture. The developer codes, tests, troubleshoots, and optimizes the CMS to ensure functionality and user-friendliness. They also integrate the CMS with other software like CRM or e-commerce platforms. Moreover, they provide training, support, and updates, ensuring the CMS remains secure, efficient, and up-to-date. Thus, they play a vital role in enabling companies to manage their digital content effectively and efficiently.