we are going to start the migration project from existing cms to aem
looking to some precise scenarios
1) what type of test conditions to include to identify the performance capacity of author server (we know for publish instances we have standard conditions)
also other tips for migration project will be helpful.
Go through below community thread, @BrianKasingli has already explained the approaches to migrate from other CMS to AEM.
For performance testing, you can explore Adobe's tough day tool.
Here are some useful links