Thank you, I will look into KWin.
Turns out, it is awesome and does more than I need. I already move a lot of my applications with xdotool to prediscribed positions and sizes, via hotkeys, which start some scripts. Now I found out, it also can move them across virtual desktops. Nice :)
To crawl I use playwright and cheerio to traverse through the html. I startet with another library, but playwright is more stable in my opinion (or just in my use Case). After the crawl I use nodecron to send Mails with nodemailer to myself, on a daily basis. All together it is a node.js app I wrote, inside a docker container.