[AznHisoka]

Elasticsearch is much more than a search engine.

Lots of people use it for analytics (checkout their aggregation/time series queries) as well as analyzing huge logs. Some people are starting to use it for machine learning use cases too.

[barbecue_sauce]

I have seen it used almost exclusively for logging as part of the Elastic (formerly ELK) stack.

[ryneandal]

At my previous job we used it for a fair amount of analytics for our SaaS clients.

[nikonyrh]

Even the "plain" ELK uses aggregations to produce those graphs.