What does SAP LeanIX recommend you do before you start the initial data upload into...

Before starting the initial data upload into SAP LeanIX, it is recommended to run an SAP LeanIX survey to gather data from stakeholders. This approach ensures that the information collected is accurate, up-to-date, and reflects the insights and knowledge of those who manage and interact with the IT landscape. Surveys provide a structured way to collect comprehensive data on applications, technologies, and business processes, which can then be imported into SAP LeanIX for a more accurate representation of the organization's IT environment.

References:

LeanIX Data Collection Best Practices

SAP Community on LeanIX Data Upload