Hi Thomas Loidolt
Thankd for contacting Syncfusion support.
We have checked your query with “rotate the SfDataGrid from horizontal to vertical view” and as of now SfDataGrid doesn’t have support for orientation.
Could you please check wether your requirement can be achieved by using SfListView control? But it comes with a limitation. The data can only be visually rendered or displayed matching your requirement , whereas the whole table will be considered as a single template (row) thus preventing you from performing row wise, column wise or cell based operations. (eg : To get data of a particular row etc). Please find the below UG Link in which list view items arranged horizontally.
Regards
Vigneshkumar R