It’s a bad look to be leaving jobs every 6-18 months repeatedly, but one or two incidences won’t tank your career.

The FB offer looks like a great opportunity, but if you only stay there a year, you’re designing a resume that will get you labeled as a job hopper and screened out of a lot of future roles at the resume stage.

Whichever you choose - the current job or FB - I suggest you make sure you stay there for at least 2 full years before making your next move, whether to grad school or another company.