Haystack
RAG & knowledgedeepset's open-source framework for composable, production-grade search and RAG pipelines.
Haystack treats a RAG system as a pipeline of components — retrievers, rankers, generators — wired into an explicit graph. That structure makes a pipeline easy to inspect, test, and swap pieces of without rewrites.
It is built by deepset with production use in mind, and its component model keeps complex setups (hybrid search, multi-stage ranking) legible rather than tangled.
Where it's ideally used
A good fit when a RAG system is non-trivial and you want every stage as an explicit, testable, swappable component.
Where it doesn't fit
The pipeline structure is overhead for the simplest "embed and answer" case where there is nothing to compose.