Developers can retire by late 30's if the wages right now keep up with inflation. Using conservative Google compensation:

22 yrs: L3, $160k total comp

25 yrs: L4, $210k total comp

27 yrs: L5, $260k total comp

32 yrs: L6, $320k total comp

39 yrs: L6, $320k total comp

Averages:

22-25: $180k avg

25-27: $230k avg

27-32: $280k avg

32-39: $320k avg

3 * 180 + 2 * 230 + 5 * 280 + 7 * 320 = 4.64 mil

4.64 mil * 0.6 (taxes/FICA) = 2.784 mil

2.784 mil - ($30k living costs/yr) * 17 yrs = 2.274 mil

Enough to retire if you don't have a kid