[Listen Notes] Upgraded Elasticsearch to 9.4.2 and Accelerated Re-indexing

We’ve upgraded our Elasticsearch cluster to v9.4.2 and further optimized storage utilization by removing unused index attributes.

We also improved our re-indexing pipeline, making it 4× faster than before. As a result, we can now re-index the entire podcast database in under 24 hours.

In addition, we re-provisioned the Elasticsearch cluster using newer storage-optimized EC2 instances, delivering better performance while reducing infrastructure costs.