If you have both Dynamic Re-Ranking and Personalization enabled for a query, you may receive the boolean parameters: persoImpactInsideActivationWindow and reRankingActivated in your search response.
persoImpactInsideActivationWindow: true indicates that the results are personalized based on the user's user profile.
reRankingActivated: true indicates there was not enough information in the user's user profile to personalize the results, so the results have been ranked using Dynamic Re-Ranking.
You can read more about how Personalization fit's into Algolia's Relevance Strategy.