Java has a vast ecosystem of APIs, not all of which are effective or easy to learn. Developing a good API is not trivial: misdesigning key elements, defining simple abstractions, and threading models are among the themes that must be addressed. The official Elasticsearch Java SDK is a project with a design effort that has been made to address these elements. Recently, this project surprised me, and I tried to examine the design ideas that make it interesting and effective, while also having som
