<p>Power BI developer create custom visuals by either using Power BI’s inbuilt visualizations or developing custom visuals using tools like Power BI’s Custom Visual SDK. They leverage JavaScript, TypeScript, and D3.js to design visuals tailored to specific business needs. These visuals are then embedded into Power BI reports, enhancing data interactivity and clarity. Custom visuals allow developers to present data in a way that standard visuals cannot, providing deeper insights into specific metrics or KPIs. Once created, these custom visuals can be shared across reports and dashboards, offering a personalized and insightful reporting experience.</p>