ELK stack (Elastic Stack)

ELK Stack (now officially the Elastic Stack) is a collection of four open-source tools—Elasticsearch, Logstash, Kibana, and Beats—used for log management and observability. It allows you to collect, search, and visualize data from any source or format in real-time.

For engineering teams, the ELK stack is a necessity for centralized logging. Instead of manually grepping through log files on dozens of different servers, you use a single Kibana dashboard to query the entire system. This lets you quickly find the root cause of an error, track security breaches, or monitor infrastructure performance. It turns raw, scattered logs into clear metrics that help maintain high availability.