Be Aware of the Makefile Effect

I have an alternate theory: about 10% of developers can actually start something from scratch because they truly understand how things work (not that they always do it, but they could if needed). Another 40% can get the daily job done by copying and pasting code from local sources, Stack Overflow, GitHub, or an LLM—while kinda knowing what’s going on. That leaves 50% who don’t really know much beyond a few LeetCode puzzles and have no real grasp of what they’re copying and pasting.

Given that distribution, I’d guess that well over 50% of Makefiles are just random chunks of copied and pasted code that kinda work. If they’re lifted from something that already works, job done—next ticket.

I’m not blaming the tools themselves. Makefiles are well-known and not too verbose for smaller projects. They can be a bad choice for a 10,000-file monster—though I’ve seen some cleanly written Makefiles even for huge projects. Personally, it wouldn’t be my first choice. That said, I like Makefiles and have been using them on and off for at least 30 years.

> That leaves 50% who don’t really know much beyond a few LeetCode puzzles and have no real grasp of what they’re copying and pasting.

Small nuance: I think people often don’t know because they don’t have the time to figure it out. There are only so many battles you can fight during a day. For example if I’m a C++ programmer working on a ticket, how many layers of the stack should I know? For example, should I know how the CPU registers are called? And what should an AI researcher working always in Jupyter know? I completely encourage anyone to learn as much about the tools and stack as possible, but there is only so much time.

If you spend 80% of your time (and mental energy) applying the knowledge you already have and 20% learning new things, you will very quickly be able to win more battles per day than someone who spends 1% of their time learning new things.

Specifically for the examples at hand:

- at 20%, you will be able to write a Makefile from scratch within the first day of picking up the manual, rather than two or three weeks if you only invest 1%.

- if you don't know what the CPU registers are, the debugger won't be able to tell you why your C++ program dumped core, which will typically enable you to resolve the ticket in a few minutes (because most segfaults are stupid problems that are easy to fix when you see what the problem is, though the memorable ones are much hairier.) Without knowing how to use the disassembly in the debugger, you're often stuck debugging by printf or even binary search, incrementally tweaking the program until it stops crashing, incurring a dog-slow C++ build after every tweak. As often as not, a fix thus empirically derived will merely conceal the symptom of the bug, so you end up fixing it two or three times, taking several hours each time.

Sometimes the source-level debugger works well enough that you can just print out C++-level variable values, but often it doesn't, especially in release builds. And for performance regression tickets, reading disassembly is even more valuable.

(In C#, managed C++, or Python, the story is of course different. Until the Python interpreter is segfaulting.)

How long does it take to learn enough assembly to use the debugger effectively on C and C++ programs? Tens of hours, I think, not hundreds. At 20% you get there after a few dozen day-long debugging sessions, maybe a month or two. At 1% you may take years.

What's disturbing is how many programmers never get there. What's wrong with them? I don't understand it.

You make it sound easy, but I think it's hard to know where to invest your learning time. For example, I could put some energy into getting better at shell scripting but realistically I don't write enough of it that it'll stick so for me I don't think it'd be a good use of time.

Perhaps in learning more shell scripting I have a breakthrough and realise I can do lots of things I couldn't before and overnight can do 10% more, but again it's not obvious in advance that this will happen.