Contact duplication

While using API we encountered weird behavior, which creates a lot of inconsistency on our side.
Sometimes when we are sending data to create a new contact and than send another request to create new contact only if contact with such email is not found, we are getting 2 identical contacts created in the system.
Also when we delete contacts from Infusionsoft UI and than try to access them via API, for some time we are getting Database error response - later it changes into usual not found response.
It`s like it takes some time to actually update data even if we already got an id for the record

Hi @Volodymyr_Kikh, can you give an example of the calls you’re making to determine if a contact exists and create contacts?