Typical comp shape
Mobile engineer (iOS / Android)s usually earn rsu + espp. Common employers include Apple, Meta, Uber, DoorDash. Apple mobile hires often stack ESPP on top of RSUs, which stretches concentration in employer stock.
What Montana changes
In Montana, every RSU vest, NSO exercise, and ESPP purchase carries 5.9% state tax on top of federal. For a senior mobile engineer (ios / android) with $300k+ of equity income, the state layer routinely adds $25-45k to the annual bill.
Planning cadence
For a mobile engineer (ios / android) in Montana, the three planning windows are: after each RSU vest (withholding check and sell-vs-hold), before any ISO exercise (AMT model at federal only), and in Q4 (estimated tax top-up to clear the safe harbor).