Multivalue buckets—​the terms, histogram, and date_histogram—dynamically produce many buckets. How does Elasticsearch decide the order that these buckets are presented to the user?

By default, buckets are ordered by doc_count in descending order. This is a good default because often we want to find the documents that maximize some criteria: price, population, frequency. But sometimes you’ll want to modify this sort order, and there are a few ways to do it, depending on the bucket.