In a world where self-service and speed of delivery are key priorities in any reporting BI solution, the importance of creating a comprehensive and performant data semantic model layer is sometimes overlooked.
We have seen quite a few occurrences where the relational data store such as Azure SQL Database and Azure SQL Data Warehouse are well structured, the reporting tier is well presented whether that is SQL Server reporting services or Power BI, but still, the performance is not as expected.
Read about it in the Azure blog.