i try to keep it secure by minimalism because the less complicated is the software the smaller is the chance of a vulnerability

so everything related to file transfer/access uses sftp (with accounts with no ssh permissions because: 1. i dont want the password to my server to be stored anywhere in some sftp software 2. im not the only user of this server) and for other services i just run a small local program and remote access it with ssh

i guess the biggest secuity threat is someone physically stealing the backup disk or the main hard drive because theyre both unencrypted