Disclosure: I work at Amazon on cloud infrastructure, but not on the codebase in question. I helped with parts of the blog post to try to explain some of the nuance about how things are set up with Elasticsearch as an "upstream".
The 9 PRs were only to demonstrate working in the "upstream first" practice, and aren't exhaustive. It also doesn't cover the additional work in the Apache Lucene project that benefits Elasticsearch as well, which is where larger code investments are being made (since that's the right place for them to live, for much of what's being built).
The 9 PRs were only to demonstrate working in the "upstream first" practice, and aren't exhaustive. It also doesn't cover the additional work in the Apache Lucene project that benefits Elasticsearch as well, which is where larger code investments are being made (since that's the right place for them to live, for much of what's being built).