As we see in Avengers: Infinity War, not only does Thanos have the gauntlet but
he also collects all the stones.
However... how did he know what was needed to house the stones? I am not too bothered by "a mystical item forged by dwarves using a collapses star so it will have special powers", but more the physical size and more specifically why the slot for the Soul Stone is 3 times larger than the others.
The first time we get to see the size of an Infinity Stone is in Guardians of the Galaxy. Equally the Mind Stone is seen in Avengers: Age of Ultron, once its case is destroyed. All the other stones are encased in some medium but it would be safe to assume they are all the same physical size.
And then we have the Soul Stone. Is there any in-universe explanation as to how Thanos came to the knowledge of the actual size to design a gauntlet that could physically house them?