Reindexing millions of documents across 10 Elasticsearch indexes was taking hours, long enough that it only ran on weekends. With a growing number of custom Normalizers slowing things down, Symfony's Serializer wasn't cutting it anymore.

We built a proof of concept with Symfony's JsonStreamer to see if it was as fast as advertised.

This talk is an honest account of that journey: the challenges, what we learned, and how it could apply to your application as well.