@Christian_Dahlqvist @dadoonet, I think the problem I was having with performance was because I has some large text fields (Large enough that they violated max field length! https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking-changes-7.0.html#_limiting_the_length_of_an_analyzed_text_during_highlighting)
I solved that length issue by indexing those large fields as term_vectors.
Now the question is, how to tune the query performance from kibana with these term_vector fields?
Is there a way I can exclude these large text fields when it is unnecessary? (But those large text fields should still remain searchable)