A Microsoft Visio developer designs, builds, and maintains Visio applications, which are used for creating diagrams and flowcharts. They utilize the software's functionalities to create visually appealing and understandable representations of complex data and processes. Their responsibilities include understanding user requirements, creating custom shapes and templates, integrating Visio with other Microsoft applications, and troubleshooting any issues. They also ensure that the diagrams are interactive and easily editable. In addition, they may work with other developers and stakeholders, providing them with technical support related to Visio applications. Their goal is to enhance data visualization and process understanding.