Databricks, Quora or Asana?

For an internship, is there a company that's generally perceived as the best choice? Leaning towards Databricks because it seems to have interesting work and I would like to apply to grad school in the near future (being surrounded by researchers seems good for that purpose). However I've also heard some negative comments about technical debt and culture.

I'm mainly looking to maximize learning and impact on the product. Pay is not really important since they're all very similar.