Vitess today is not the Vitess of 2021. About 70% of the current codebase was written in the last five years, based on lessons we learned running it at scale.

Neki is built for Postgres from the ground up, by the engineers who did that work.

On the Multigres comparison, I'll admit we get a bit salty, mostly because "Vitess for Postgres" invites the comparison. But to date there's no public evidence of a working sharding implementation in Multigres. Their sharding design doc landed this week, and it lists cross-shard query planning and resharding execution as explicitly out of scope.

Neki does sharding today, including online resharding that switches traffic without a maintenance window. It isn't open source, but you can spin up a cluster and try it yourself.