Has anyone here Horizontally scaled a WordPress Project ?

These days, it is so easy to Vertically scale WordPress and you do that via so many providers letting u add more RAM and CPUS.
However, you will eventually hit limits event with this approach where things start to bottleneck due to WordPress architecture.

The only way to be able to scale without running into bottleneck issues is to scale horizontally. Something like leveraging ludicrousDB where you split your read and rights or using a service such as MYSQL Heatwave.

So my question is, are there any individuals that can share how they have scaled horizontally their WordPress websites ?