Recommended resources to consider:

* Code Complete https://www.amazon.com/Code-Complete-Practical-Handbook-Cons...

* Programming Pearls https://www.amazon.com/Programming-Pearls-2nd-Jon-Bentley/dp...

* Pragmatic Programmer https://www.amazon.com/Pragmatic-Programmer-Journeyman-Maste...

The Pragmatic Programmer: From Journeyman to Master https://www.amazon.com/Pragmatic-Programmer-Journeyman-Maste...

This book seems to be a classic for programmers.

I give these three books out to new managers in my org:

* High Output Management by Andy Grove https://www.amazon.com/gp/product/0679762884/

* Turn the Ship Around by David Marquet https://www.amazon.com/gp/product/1591846404/

* The Score Takes Care of Itself by Bill Walsh https://www.amazon.com/gp/product/1591843472/

For interns I give out these two books:

* The Pragmatic Programmer https://www.amazon.com/Pragmatic-Programmer-Journeyman-Maste...

* The Passionate Programmer https://pragprog.com/book/cfcar2/the-passionate-programmer

As a 54 year old alum:

Unless you've been seriously programming for a number of years, with a fair amount of that in teams, including face to face ones, you're probably not nearing your peak. I'd suggest reading The Pragmatic Programmer: From Journeyman to Master (http://www.amazon.com/The-Pragmatic-Programmer-Journeyman-Ma...) and judge where you are in the range from journeyman to master.

If you're looking for "lock-in", i.e. be easily employable past your ability to fake looking under 35, I'd suggest getting a job with a serious security clearance, which can be a trick, or specialize in one of the fields that respects grey hairs like embedded (but only so much depending on the sub-field, e.g. Detroit car companies at least in times past recruited heavily from Course 6 because they too got rid of their older EEs and programmers).

If you goal is to really work for yourself, and you think you can eventually bill at a rate 5-6 times the income you want to receive---maybe talk to some professors who make a lot of money on their one day a week dedicated to that, albeit they do it with MIT Professor on the CV---yes, that's a very good way to go. But hard for most people. See e.g. this comment https://news.ycombinator.com/item?id=9499561 which points out you have to compete on quality, not price, and a couple of HN contributors who've written a lot about that.

Medicine: in a county, or the developed "West", where people by and large don't directly pay for their own medical care, and those who do pay are looking at a rapidly graying population, well, it's a field you ought to run screaming from, unless it's your calling.

Don't know about MechE and so on, in general you need to talk to older engineers, the people who run the department, professors, etc., of course adjusting for selection bias. If you haven't already identified a calling, well, you have a lot of options, especially if you're strong at math. Especially before the 2008 crash, a lot of EE strong and therefore math strong EECS graduates would get initial jobs in finance with their proven math chops, which if they were smart got them in a good financial position to do something they really wanted to do later.

I'm a huge believer in going back to primary texts, and understanding where ideas came from. If you've liked a book, read the books it references (repeat). I also feel like book recommendations often oversample recent writings, which are probably great, but it's easy to forget about the generations of books that have come before that may be just as relevant today (The Mythical Man Month is a ready example). I approach the reading I do for fun the same way, Google a list of "classics" and check for things I haven't read.

My go to recommendations:

http://www.amazon.com/Structure-Scientific-Revolutions-50th-... - The Structure of Scientific Revolutions, Thomas Kuhn, (1996)

http://www.amazon.com/Pragmatic-Programmer-Journeyman-Master... - The Pragmatic Programmer, Andrew Hunt and David Thomas (1999)

Things I've liked in the last 6 months:

http://www.amazon.com/How-Measure-Anything-Intangibles-Busin... - How to Measure Anything, Douglas Hubbard (2007)

http://www.amazon.com/Mythical-Man-Month-Software-Engineerin... - Mythical Man Month: Essays in Software Engineering, Frederick Brooks Jr. (1975, but get the 1995 version)

http://www.amazon.com/Good-Great-Some-Companies-Others/dp/00... - Good To Great, Jim Collins (2001)

Next on my reading list (and I'm really excited about it):

http://www.amazon.com/Best-Interface-No-brilliant-technology... - The Best Interface is No Interface, Golden Krishna (2015)

There is a great chapter in The Pragmatic Programmer on why you should stick with text files for everything possible. Section 3 / Chapter 14 "The Power of Plain Text". It argues that as programmers, our base material as craftspeople isn't wood or metal, but knowledge, and with plain text we have the ability to manipulate knowledge with virtually every tool at our disposal.

http://www.amazon.com/Pragmatic-Programmer-Journeyman-Master...

This blog post doesn't express things nearly so well as the book, but the argument has validity.