For Rust-based Kafka alternatives, I like Tansu[1]. It at least provides Kafka API parity, and critically also gives users a pluggable backend (embedded SQLite, S3 for low cost diskless type workloads and Postgres because just use Postgres)

It’s nice to try and out innovate Kafka, but I fear the network effect can’t be beaten unless the alternative is 10x better.

Something like Warpstream’s architecture[2] had a shot at dethroning Kafka, but critically even they adopted the Kafka API. Sure enough, Apache Kafka introduced a competing feature[3] within two years of warpstreams launch too.

[1] - https://github.com/tansu-io/tansu [2] - https://www.warpstream.com/ [3] - https://topicpartition.io/blog/kip-1150-diskless-topics-in-a...