This article provides guidance that enables developers and administrators to produce and maintain optimized Power BI solutions. You can optimize your solution at different architectural layers. Layers include:
https://docs.microsoft.com/en-us/power-bi/guidance/power-bi-optimization
Increasing the performance of the reports are very important for the user experience when working with Power BI. In this article I will go through how you can increase the performance of your reports in regards to the data sources, data model, visualization and other aspects.