I saw in document, it wrote: “Note: Changes made through this endpoint are processed asynchronously, so can take several minutes for changes to be applied to contact records.”
It means the request will be responded immediately and the process of updating will run in the background, so how can we check whether the updating contacts is done or not?
In my case, I have to get contact properties updated by bulk api above, so I need to check the finishing of the bulk update and then call get_batch_by_email request to get contact properties history.
There’s no built-in notification when a batch of contacts is finished being asynchronously created/updated. You might consider using the webhooks API to subscribe to contact creations/updates to get notified when these contacts are updated. Alternatively, you could make requests to the recently created / recently updated contact endpoints to pull the most recently modified contacts until you’ve pulled the info on all of the relevant contacts.