I'm also getting this error surprisingly often at the moment (after <5 minutes of starting a bulk upload). From Lightroom uploading: "The MediaWiki error backend-fail-internal occured: An unknown error occurred in storage backend "local-swift-codfw"." I've also had the same error when uploading a new version of a file.

The categorisation of the files I get the error message after uploading aren't showing up in the watchlist as well, if that helps (just the file upload shows, not the categorisation - while for the previously uploaded image both show).

Examples where the error happened, in case those are useful:
https://commons.wikimedia.org/wiki/File:At_Sudbury_Hall_2023_092.jpg
https://commons.wikimedia.org/wiki/File:At_Sudbury_Hall_2023_017.jpg
https://commons.wikimedia.org/wiki/File:At_At_Santa_Cruz_de_Tenerife_2023_119.jpg
https://commons.wikimedia.org/wiki/File:At_At_Santa_Cruz_de_Tenerife_2023_116.jpg
https://commons.wikimedia.org/wiki/File:At_At_Santa_Cruz_de_Tenerife_2023_107.jpg
https://commons.wikimedia.org/wiki/File:At_At_Santa_Cruz_de_Tenerife_2023_092.jpg

Adding SRE-swift-storage as this is about swift per error message (please add such project tags if possible - thanks).

Also see T328872: Commons: UploadChunkFileException: Error storing file: backend-fail-internal; local-swift-codfw