How long has Supreme Leader Snoke been around?

Question

SL Snoke looks like he has been around for a while, I am wondering where he was when the Empire ruled the Galaxy?

Did Darth Sidious and Darth Vader not sense his presence in the force?

Answer 1

Assuming we take Snoke's word for it, Snoke is at least 53 years old; he claims to have watched the rise and fall of the Empire, which rose in Episode III, itself taking place 53 years before The Force Awakens.

Moreover, the idea of Snoke's presence being subject to Force senses works against two factors: his skill, and his ability.

We don't know anything about Snoke's skill in the Dark Side; he may not even have Force abilities, or he may be skilled enough -- as Sidious and his master were -- to cloak his presence.

Moreover, we don't know when he began working on the Dark Side, if ever. He could have been an untrained child.

There's simply too many variables, and too little information, to answer this question yet.