Elasticsearch 7.11 introduces runtime fields, a schema on read feature that complements its existing schema on write mechanism, offering users enhanced flexibility in querying and indexing data. Unlike traditional indexing where all fields are predefined and stored at ingestion, runtime fields allow for fields to be created and evaluated at query time, enabling dynamic data exploration without the need to reindex. This innovation is particularly useful for adapting to changing data formats, correcting indexing errors, and iteratively refining data structures. Runtime fields are integrated within the existing Elasticsearch platform, facilitating seamless use alongside indexed fields without additional procedural overhead. This approach empowers users to balance performance and flexibility, making it easier to adjust data structures as needed and supporting more efficient and cost-effective data management. The feature is currently in beta and further enhancements are planned to expand its capabilities in Kibana, including UI tools for field creation and query customization.