Developed the Apache Doris 4.1 vector database backend integration for RetrieveEngine in the Tencent/WeKnora repository, enabling parity with other vector stores such as Qdrant and Milvus. Focused on backend development using Go, the work included implementing MySQL protocol support for DDL and queries, upsert operations via Stream Load, and asynchronous indexing. Enhanced deployment reliability by adding Docker Compose templates, environment variable support, and health checks. Integrated Doris-specific configuration for multi-instance setups and ensured robust quality through comprehensive unit testing and documentation. This integration allows RetrieveEngine to leverage Doris as a scalable, production-ready vector backend for improved retrieval performance.