This document discusses how Telemach Slovenia leveraged open source big data technologies like Elasticsearch, Logstash, and Kibana (ELK stack) to build analytics dashboards for fraud detection and network monitoring. It summarizes their initial success building a roaming fraud dashboard in 8 days using these technologies. This proof of concept led them to expand usage to additional fraud and network performance dashboards. The ELK stack provided scalable and cost-effective log analytics capabilities compared to commercial options like Splunk. This enabled both IT and business users to gain new visual insights into network operations and issues.