Elasticsearch - Massive Indexing takes too long?

Hello , hope you do fine guys!

If anyone has ever worked with Elasticsearch on a production enviroment?

Here is the my main problem.

If we have to index like 50k (which is not so much data) Products to ES , we have to wait for HOURS to finish the reindexing thing, which always hurts. We actually need this very often, because for example we need to change the mapping on STAGING environment to test things , etc.

We index them like that:

We fetch the needed data for each product (many many fields , containing relations , etc)

We send the request to BULK API (but it still indexes them 1 by 1 I think)

Does anyone know a way to index things somehow faster? In minutes for example?

Thanks!