Validate that the problem is real
I look for the workflow where the problem appears, who repeats it, and what they use today. If the demand only exists in my imagination, it is not yet a product signal.
Validate the entry point
An indie product needs a natural path to discovery. That path can be search, community discussion, tool directories, short content or a fixed pain in a workflow.
Shrink the first release boundary
The first version should help a user complete one real task. Fewer features are not automatically better. Every feature has to serve the validation.