It is often translated as “I think, therefore I am”, but this doesn’t seem to be a very accurate translation. Without any particular knowledge of latin, it seems that the word cogito is more related to cognition, which means knowing or awareness.
So a more accurate translation seems to be “I am aware, so I exist”, or rather “Awareness – so Existence”, and this is indeed very close to the advaita – and many other – traditions.
I am pure awareness, and that is all I can know with any certainty. Anything else, the whole world of phenomena, comes and goes and my views of it is subject to errors.