Selfhosted

I just use Calibre-Web-Automated. I'm not a hoarder, I usually get one book at a time and I add it via the CWA web interface, often on my phone. Then I download it to my KOReader Tolino via OPDS.

While CWA indeed seems to be optimized for fully automated piracy, it's working fine for the above-mentioned workflow as well.

I've been on Calibre Desktop before, which I used in a similar way, just with Syncthing instead of OPDS.

Bunch of folders by general theme.

Grimmory all the way. Once I tried it I haven't gone back to my CWA deployment at all. Also, Shelfmark is pretty cool.

Openbooks downloading to Calibre's auto ingestion folder, all running as a docker compose. OPDS service feeds FBreader on an Android tablet.

I kind of railroaded myself into using calibre unfortunately.

I have a very specific filenaming scheme which I originally came up with back when I only used folders for organising my books in order to group together books that belong to a series but where the series is part of a larger universe.

Basically my folder structure is {World}/{Reading Order}; {Series} #{Series_Index} - {Title} - {Author}

On my kobo I have the autoshelf plugin installed which automatically parses this information when I add books and groups them together by world while filling out the series information.

In order to properly make use of this system I need to use Calibre custom columns and be able to export the books I want with this specific name format. I have yet to find a program other than calibre that would support this.

It would probably be smarter for me to reorganize my books at some point but I really like being able to basically drop a ton of books at once onto my reader using SFTP and as far as I can tell all common options rely on manually downloading the books, sending them directly to the reader or pulling them from their internal file storage in whatever form the application stores them...

I do like Audiobookshelf for the ability to add a book to multiple series, but the missing mass export functions stop me from switching

Just today I tried switching from Calibre on my Desktop to calibre-web-automated. But after about an hour of fiddling and searching, I went back to calibre on my PC.

I couldn't get KOreader on my kindle to simply sync books that I add to my library to my ereader wirelessly.

The best I could manage is use KOreader to subscribe to CWAs OPDS feed, but that doesn't automatically add new books, I would have to manually go to the OPDS feed and download the books. And apparently, kosync is only able to sync reading progress.

With Calibre on. My desktop, I simply start the program on my PC, enable WiFi in Koreader and new books get automatically downloaded.

CWA largely removes the need for running Calibre.

I use CWA for the main book "hub" and upload everything (audiobooks and comics too) to it. Then I have audiobookshelf scan the calibre directory, and Komga do the same because the app I use for comics (cdisplayex) doesn't sync with Koreader yet.

On the client side I use Koreader, Lissen and Cdisplayex.

It works fine but it would be nice to have one app that syncs all progress. And my holy grail is one that can sync ebook and audiobook progress like Amazon's whispersync!

I'm pretty locked in to Calibre myself. I use a plugin called fanficfare to collect web fictions I like, which generates epubs and updates them when the stories get updated. Across those and regular books I've got about 6k books in my digital library. Right now it just runs on my desktop, but I'd like to move it to my server at some point.
As for actually reading them, I either plug in my kobo and manually sync/add books that way, or use the now discontinued Calibre Companion app on android to do the same on my phone. Unfortunately I haven't found an app that is good enough to replace it for my needs, so I just deal with the app being unstable on the current version of android.

I like audiobookshelf since I can self host it and listen to my podcasts. But I’ll admit it does have some issues visually when trying to read on the iOS or iPadOS app. The web view is great though.

I use mylar3 going to a comics folder and lazy librarian going to a books folder. I use IRCHighway for any books I have trouble finding. They handle the metadata well enough. Kavita is my reader of choice. 

What version of Calibre-Web are you using? Mine has support to upload an image for a cover. I'm just using the latest docker image from ghcr.io/linuxserver/calibre-web.

My current workflow is pretty basic, I took my Calibre library I already had, dropped it into Calibre-Web and moved to a fully web based setup (so I don't use Calibre at all anymore, just Calibre-Web). I've got the Kobo integration working too so I can mark books to sync to my device through the browser and then just sync my Kobo wirelessly.

I tend to use the Kobo store to purchase new books so I'm a bit lax about grabbing local copies of everything, but whenever I do get new books I can upload them into Calibre-Web, edit the metadata after I match the book, and then I'm good to go. But I also don't add books that often at the moment, so haven't seen much point in investing much time into further automation.