Imo IAM aka OIDC is keeping it simple.
Do you want to develop your own auth solution, or focus on features of your service?
For the rest, of course. AWS, GCP, Azure, all too expensive.
Chances are very high you won't even need more than 3 machines, if you'd like to play it safe, 1 if downtime is acceptable.
The challenge is long term.
You need to be able to switch after EOL of your current OS version, and easily.
Data is something that's expensive. It requires constant backups. Snapshots.
If you can afford it, have a dedicated machine or cluster for data.
This way you can swap the webapi layer when you receive better offers over the years (cheaper hardware, EOL OS, etc)
Do think in blocks or components and layers, but I'm guessing you do that anyway.
What cloud does is it adds convenience for ridiculous costs.
Personally I have an incubation server where all trials and or developing projects are hosted.
Once and if something takes off, it receives dedicated hardware.
In the unlikely case that this dedicated setup isn't enough I'll start thinking about cloud.
But even in that case, I'm pretty sure, a private cloud with dedicated personnel is cheaper than AWS etc
For the rest, of course. AWS, GCP, Azure, all too expensive.
Chances are very high you won't even need more than 3 machines, if you'd like to play it safe, 1 if downtime is acceptable.
The challenge is long term. You need to be able to switch after EOL of your current OS version, and easily. Data is something that's expensive. It requires constant backups. Snapshots. If you can afford it, have a dedicated machine or cluster for data. This way you can swap the webapi layer when you receive better offers over the years (cheaper hardware, EOL OS, etc) Do think in blocks or components and layers, but I'm guessing you do that anyway.
What cloud does is it adds convenience for ridiculous costs.
Personally I have an incubation server where all trials and or developing projects are hosted. Once and if something takes off, it receives dedicated hardware. In the unlikely case that this dedicated setup isn't enough I'll start thinking about cloud. But even in that case, I'm pretty sure, a private cloud with dedicated personnel is cheaper than AWS etc