This is not for extreme beginners. Please make sure that you know what you are doing and what your requirement is before following this guide. Note that the this is not an exact step-by-step guide. However, it will cover everything in an almost step-by-step way. This is based on AlmaLinux 10 - a redhat based, free, enterprise-grade operating system. This is my journey trying to harden this, while learning new things on the go!
There's a backstory behind this blog post but publicly sharing it is not the greatest idea. This post will cover some interesting hardening ideas to protect your VPS. Note that this is not a step by step guide; rather, this provides an overview of some cool things you could do. Everything mentioned here is just surface level.
If you don't like big tech companies prying their eyes on your data, you might want to self host all the services either locally on-premise or on a cloud server (a Virtual Private Server or a Dedicated Server).
When you are doing this, yes, you are safe from the eyes of big tech, and you actually get to have some privacy. HOWEVER, you will be in charge of your own data security. Therefore, hardening your server is essential to keep your data secure from bad actors and sometimes even automated scanners.
In this article, let's see how to do just that. This guide focuses on Debian 12 (not Ubuntu, since it's Canonical's bloat). Let's get started.