We use it in Freepik, Flaticon and Slidesgo. It has a good performance and I find the source code easy to read / understand. It lacks some features from Elastic

We use it in Freepik, Flaticon and Slidesgo. It has a good performance and I find the source code easy to read / understand. It lacks some features from Elasticsearch, like CJK tokenizers, but we were able to work around that. Very stable, fast, and easy to connect to mysql.