Code Retrieval Rankings Are Pipeline-Dependent: Study Reveals Configuration Trumps Model Choice

Developers often assume that selecting the best embedding model is key to Code-RAG performance, but new research challenges this assumption. A comprehensive benchmark study on Apache Kafka shows that retrieval accuracy depends equally on chunking strategy and retrieval mode—changing the pipeline configuration can completely reverse model rankings. This finding implies that optimizing Code-RAG systems requires holistic pipeline design rather than model selection alone.