Elastic's Advent Calendar 2019 presents a diverse array of topics related to the Elastic Stack, shared by their engineering team through daily posts in multiple languages over the first 25 days of December. This initiative, inspired by previous years' success, covers subjects ranging from Elasticsearch's integration with Python for data scientists, to monitoring shell commands in Linux using Auditbeat, processing Mailgun activity with Elasticsearch, and exploring the Elastic Common Schema (ECS) with Kibana. Additionally, the series delves into configuring JVM options in Elasticsearch and the intricacies of Elastic's unsupervised machine learning anomaly detection models. Each post aims to engage the community with insightful technical content and invites feedback to enhance future offerings.