"Every 2 minutes, the last 1000 HN items (stories, comments, polls) are sent to Algolia's indexing API. Items from the last 48 hours are refreshed every hour."
Correct, and we're planning to move to the new official API ASAP (instead of the legacy one -> it was not web crawler but far from perfect) for the indexing.
Regarding the REST APIs, let's keep both for now :)
From the hnsearch about page:
"Every 2 minutes, the last 1000 HN items (stories, comments, polls) are sent to Algolia's indexing API. Items from the last 48 hours are refreshed every hour."