It is easy to design a personal project as if it were a startup expecting millions of users. In practice, a single modest virtual machine handles far more than most hobby projects will ever need.
Care beats scale
What matters more than capacity is maintenance: automatic backups, a restore you have actually tested, security updates, and the habit of reading the logs once in a while. A small server that is looked after beats a large one that is ignored.
- One machine, one place to look when something breaks.
- Unattended security updates switched on from day one.
- Backups that leave the machine every night.
- A short text file describing what runs where and why.
When to grow
Add a second machine when you have a concrete reason — not because a diagram looks more impressive with three boxes. Real reasons are rare: a service that must survive a reboot of the first one, or load you have actually measured.