I'm one of the co-founders of PowerSync [1]. We did a Show HN last year [2]
PowerSync is a Postgres<>SQLite sync engine. We spun it off from an industrial app platform where the core sync system has been in production for more than a decade and is in daily use in heavy industry. We reached the v1.0 milestone of the PowerSync stand-alone product late 2023. Details on consistency can be found in our docs [4]
We recently opened the source code and made the system self-hostable for free [3]. We also have a cloud-hosted/SaaS option.
I believe there's a few users of ours in the HN community. Happy to answer any questions.