LocalStack for AWS 4.11 introduces several improvements aimed at enhancing AWS parity across various services, including new Lambda runtime support for Python, Java, and Node.js, expanded API support for Amazon Managed Streaming for Apache Kafka (MSK), S3 Tables, and CodePipeline, along with improved AWS Key Management Service (KMS) emulation capabilities. The release also focuses on facilitating the testing of machine learning workflows with RDS support for the pgvector extension and enhances the persistence of EKS cluster contents, allowing for more efficient local testing of Kubernetes workloads. Additionally, the update addresses several bug fixes and deprecations, such as the planned removal of the host mode for LocalStack CLI in favor of Docker mode by January 2026, while encouraging users to upgrade to the newest version to benefit from these advancements.