Software Engineer Fat FIRE: High-Income Retirement Strategy
FIRE Number
$3.0M
Target Retirement Age
45
Years to FIRE
17
Monthly Savings Needed
$6K
Software engineers are the most represented profession in Fat FIRE communities and the most capable of achieving it quickly. Senior engineers at FAANG companies earn $250,000–$500,000+ in total compensation — base salary, bonus, and RSU grants. At $300,000 TC saving $8,000/month from $200,000 starting balance, $3M is reached in about 14 years. At $400,000 TC saving $12,000/month, it is 9–10 years. Fat FIRE at 40–50 is a realistic planning target for mid-career tech professionals.
RSU tax management is central to SWE Fat FIRE. RSUs vest as ordinary income at the highest marginal rate (32–37% federal for most senior engineers). The standard advice: sell RSUs immediately upon vesting and invest in diversified index funds. Holding employer stock creates concentration risk — if your company's stock drops 50% and you have held $400,000 in unvested/vested RSUs, your portfolio takes a hit unrelated to your FIRE progress. Diversification discipline is the highest-value behavioral choice in SWE Fat FIRE.
Mega backdoor Roth is the definitive tax strategy for SWEs at major tech companies. Google, Meta, Microsoft, Amazon, and many others allow after-tax 401k contributions up to $69,000/year with immediate Roth conversion. A senior engineer maxing mega backdoor Roth for 15 years builds $1,035,000 in after-tax 401k contributions (before growth) entirely in a tax-free Roth wrapper — producing $2,500,000–$3,000,000 in Roth holdings at retirement. This Roth balance provides $100,000+/year in tax-free income, minimizing lifetime tax burden dramatically.
Stock option strategy in Fat FIRE: early-career or startup engineers with ISOs (incentive stock options) need careful AMT planning. Exercising ISOs before a liquidity event triggers potential AMT liability; the 83(b) election for early exercise (available 30 days from grant) can lock in a low basis and avoid AMT. For senior engineers receiving NSOs (non-qualified options), the spread at exercise is ordinary income — plan exercises across tax years to stay in lower brackets when combined with other income components.