I joined a startup two years ago as the very first non-founding engineer (right after the seed round of about 1.5M). I took a salary cut for a bit less than 2% of the company (ISOs with the usual 4 years vesting schedule). Now, two years later, I'm halfway through the vesting, we got a pretty big series A, and now my salary is market level-ish (170k) and I currently have about 1.2% of the company (after the A dilution). The last 409 valuation is around 40M.

Through recruiters (the serious kind) I got in touch with a Fortune 500 company who is building an internal spinoff, nice and interesting project. They offer me same salary and RSUs of the backing company for a floating value of 600-800k, with allocation over 3 years (30%,30%,40%).

I don't know what to do. I like my current company a lot, but I feel like this opportunity might be pretty good to put some eggs in another basket.

What would you do? Has something like this ever happened to you?