Abstract: A method includes obtaining an input query at a retriever model, where the retriever model includes a reconfigurable sequence of one or more rankers selected from among a plurality of rankers. Each ranker is configured to identify a specified number of information chunks relevant to the input query. The method also includes providing one or more of the information chunks from the retriever model to a generative model. The method further includes using the generative model to create a response to the input query, where the response is based on the one or more information chunks. The plurality of rankers includes a bi-encoder, a cross-encoder, and a large language model (LLM)-ranker.