Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

If you're trying to build it all from scratch, sure, but you specifically mentioned docker and there's plenty of high-quality docker images you can use - and it's no harder to use a qBittorrent docker image than a transmission docker image.

Here's the docker command for transmission:

docker run -d \
  --name=transmission \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=Etc/UTC \
  -e TRANSMISSION_WEB_HOME= `#optional` \
  -e USER= `#optional` \
  -e PASS= `#optional` \
  -e WHITELIST= `#optional` \
  -e PEERPORT= `#optional` \
  -e HOST_WHITELIST= `#optional` \
  -p 9091:9091 \
  -p 51413:51413 \
  -p 51413:51413/udp \
  -v /path/to/data:/config \
  -v /path/to/downloads:/downloads \
  -v /path/to/watch/folder:/watch \
  --restart unless-stopped \
  lscr.io/linuxserver/transmission:latest

and the equivelant for qBitTorrent:

docker run -d \
  --name=qbittorrent \
  -e PUID=1000 \
  -e PGID=1000 \
  -e TZ=Etc/UTC \
  -e WEBUI_PORT=8080 \
  -p 8080:8080 \
  -p 6881:6881 \
  -p 6881:6881/udp \
  -v /path/to/appdata/config:/config \
  -v /path/to/downloads:/downloads \
  --restart unless-stopped \
  lscr.io/linuxserver/qbittorrent:latest

I'm not even going to argue that the qBitTorrent docker image is technically easier as it has less to configure, it's all one command at the end of the day.

Qbittorrent-nox is available as a package on all major distors afaik. It has an official docker image aswell. Couldn't be any simpler to set up.