At the Tochigi Ruby Conference, a presentation was given on monitoring Ruby on Rails applications using the Elastic Stack, focusing on key areas such as uptime monitoring, host and application metrics, log monitoring, and application performance monitoring (APM). The demonstration involved a Rails application with a frontend composed of NGINX and Rails and a backend using PostgreSQL, incorporating tools like Metricbeat, Filebeat, Auditbeat, Packetbeat, Heartbeat, and the Elastic APM Ruby Agent to gather comprehensive monitoring data. Elasticsearch Service was used to streamline the setup for data storage and visualization, allowing for easy monitoring of server and application availability through the Uptime app in Kibana. The presentation emphasized the importance of gathering detailed logs for problem identification and the role of Elastic APM in measuring application performance internally, highlighting the emerging concept of observability, which enables the correlation of metrics, logs, and APM data in a unified platform to expedite problem-solving. The Elastic Stack facilitates this observability, offering a trial for users to explore its capabilities in monitoring and data visualization.