Finally, picswars.io is back from being hacked! Took that long because I had to ensure that security and backups are properly configured now and, well, life got into the mix.
One morning I woke up and found that my game got hacked: the whole db is deleted and replaced by a hacker's message.
Of course, negotiating with the terrorists is not an option =] So I decided to restore the db and improve the security. Luckily, I had backups, but I didn't run them frequently enough, so some data is lost (it runs more frequent now). I had to spend about 3-4 fulltime work days rebuilding the server setup in order to ensure the server security. Basically, I decided to rewrite the production setup completely. I had to do that so that I could configure everything without exploding my brains. It works now, phew!
A lesson learned: I should've used the technologies I understood right from the beginning. You shouldn't experiment with the technologies when you're building a production-level project.