Hi HN! Got nerd-sniped by the "Git at any scale"[1] blog post and made a generalized version of their S3 WAL with support for read replicas. Instead of a single WAL file like theirs, WalTier has snapshots so it can be a bit larger (GBs rather than MBs).
Source: [Hacker News](https://github.com/danthegoodman1/waltier)