Web Design Doubt: Example

[DabasarusRex]

Hello, I wasn't sure where to properly place this topic as it is about Web Design in general.

Does anyone have an idea of what a website like this could have been developed with?

I am intrigued by the movement of the letters and sections as you scroll, I don't know if this is something that can be configured using conventional platforms or if it is done with highly customized language and programming.

Thank you!