Of the MIT/Stanford software engineers I have known a long time and know what's become of them: one (60-ish now) had a fairly lucrative late career segment doing web search at Yahoo and is now retired; one (same age) is still working, doing Big Data consulting; one (late 50s) was in a two-career couple with two or three kids and is now retired; another (mid 50s) made enough in the stock market and miscellaneous other ventures to semi-retire, though he still does a little consulting; another (56) is happily in business for himself selling iOS apps; and I (57) am still working as a tech lead for HP Fortify.

I think the lesson is, if you're careful with your money in your 30s and 40s, you won't necessarily have to work into your 50s if you don't want to. Alternatively, take good care of yourself and keep learning new stuff, and you can be productive well into your 50s and beyond. But if you don't do either of those things, you may have a problem.

I'm in the same range and I would have to say that most of the people who pop to mind (caveat--there's probably some selection bias) have done pretty well.

Among people from school who I've kept in touch with. One founded a significant company. Another is Chief Scientist of a large IT vendor. (And another was--retired now--Chief Scientist at a large consumer goods company.) A few are consultants of various types. One is still a game designer (though he actually started that after school; he was a civil engineer).

I also work with a fair number of people in the same general age range. I'm sure some percentage are still primarily coding although a lot are development managers of various sorts.

Personally I worked and a Mechanical engineer for a few years but I've done technical marketing of various sorts or strategic/marketing advisory work for most of my year. (I do some programming but strictly on the side.)

Another MIT alum here in my 50s: Phil is not far off, but I think he is underestimating the selection bias for that event.

Even back in the 80s, nobody chose engineering because it is a cushy lifelong path.

Edit: BTW, many of his posts are interesting.