Here is how it is going to go, Adobe will tell their accountant to wire the money, the accountant will get the details from Figma. Adobe accountant will call their bank or maybe even go in to the branch. And tell them they are sending X to X. It will take a few stamps and confirmation and it will be done in about 5 mins. Some computer somewhere will go - 1 billion Adobe and + 1 billion Figma.

On the bank side nothing really happens unless Figma decides it wants to withdrawal all 1 billion. Then X bank will owe Y bank money, that loan will be balanced at some point. It will probably take a few days so Figma will be told it needs a few days.

Even if Figma decides to pay all their employees a share, that's also just - 50k Figma, + 50k Bob Smith in a computer somewhere.

There is no actual exchange of money until stuff is balanced at some point or you withdrawal. It's all just 1s and 0s in a record.