In the previous chapter, we saw the various steps to be configured for production readiness. We also explored the fine-tuning configuration needs to be considered during production setup for better performance. We learned how to secure a Solr, take backups, and configure logs. Then we got an overview of SolrCloud. Now we have a complete configured Solr with all the required configurations to meet any search request. In this chapter, we will learn how Solr can be used with a web application and how to call APIs in different languages. We'll have an overview of various Client APIs supported by Solr.