Would you be willing to expand on this a bit? We run multiple elasticsearch clusters and there are pain points everywhere, I wonder where vespa improves?

For us, Vespa It is in a different league. Some quick things I remember: - Native Tensor/ XGBoost support - Automatic data partitioning and auto balancing( no need to set shards before hand) - Jdisk (https://docs.vespa.ai/documentation/jdisc/) - This is the major feature for us. It enables us to create Distributed Applications that manipulate the search results directly on the nodes.

I'm not associated with the team, but I take every opportunity to promote it, as I think it is a very underrated project.