MS-MARCO MiniLM-L12 Reranker - High-Accuracy RAG on SageMaker

MS-MARCO MiniLM-L-12-v2 is the 12-layer variant of the MS-MARCO cross-encoder family with 2.9 million monthly downloads, delivering meaningfully higher reranking accuracy than the L-6 variant at moderate throughput. With 12 transformer layers processing query-document pairs jointly, it captures deeper relevance signals for complex enterprise queries -- technical documentation, legal language, financial terminology, and multi-part questions where shallow models miss nuance. At 134MB it remains fully CPU-native and deployable without GPU infrastructure. Use it when retrieval quality directly affects user outcomes: enterprise knowledge management, compliance document search, and contract review assistance where extra precision justifies slightly higher latency.