How did Tappei do it? How was Re:Zero made?

I have been recently reading some of the LN and in genuinely just in shock on

How?

How did one man come up with this story? I just down get how he managed to make such a deep and interesting world. How did he make Aldebaran? How does he come up with this stuff?

How did he manage to lay every mystery out so nicely? So captivating

I just don't get it. I want to know how. How did he do it? I want to know his process of creating a story. I can't help it. I have never been more interested in a story my whole life.

I am genuinely asking, how did he manage to fit all this world into his brain? How did he manage to keep everything so nicely connected.

I keep looking, but I can't see where he drew inspiration from. Atleast from the characters and some abilities (Like regulus)