I don't think this question has an answer, because there is no way to precisely define "knowing how to code." Here are several reasonable definitions:

1 You know how to code if you can get a simple application to run. (No requirements as to maintainability, performance, security, etc.)

2. You know how to code if you can pick the right tools for the job, foresee and avoid future maintenance problems, avoid introducing well-known security holes, and achieve an appropriate balance between performance, cost, and programming effort.

3. You know how to code if you understand your specialty inside and out, to the point where you could write a book, teach advanced classes, testify as an expert in court, and maintain a leading blog about your specialty.

#1 can probably be attained in a month. #2 will take most people several years of sustained effort. Many programmers don't reach #3, and those who do have usually been in the game for many years and have held multiple programming jobs.

So what does it mean to learn to code? What's a good enough level of expertise to code for you own business?

Good question.

Personally I consider anyone who can be given a reasonably difficult[1] problem and solve it on their own[2] as knowing how to code.

[1] reasonably difficult - something that can't be solved by finding an appropriate tutorial (in a sense, the solution has to create new knowledge in your sphere of influence)

[2] solving on one's own - not solving through code archaelogy by frankensteining a solution together from random code snippets found online and/or nontrivially stitching together othe people's API's and libraries

It takes very little coding knowledge to be able to provide massive value.

I learned to program SAS and get a job in about 2 weeks. I had a very strong Math background, but next to no programming background.

6 months later, I'd automated my job, my department's jobs, and another department's jobs.

You can argue that this doesn't count as real coding-SAS is certainly much easier than Ruby. But the point is that it was quite possible to learn enough to provide millions of dollars of business value in a couple of weeks.

Did this result in your employer letting people go?

Nope-the company was surprisingly good at reassigning people to areas that actually did need work. Except for me-it took them so long to reassign me that I got bored due to a lack of work and left.

|What's a good enough level of expertise to code for you own business?

I think it's very much depends on your goals and tools.

For example, you can probably design a useful business application in Mircosoft's lightswitch in a short time .And it would probably be reasonably secure ,maintainable etc. , because of MS's help.

Same can be said for using python + numpy as a front end for a lab equipment , used in your business.

I agree on the general notion is coding involves a lot more than meets the eye. Given that, it's probably impossible to claim that coding is learnable in anything less than years of work. Even then, we all know that we learned, one way or another, by doing. This course is design to get people writing actual code and accelerating what can be a slow learning experience. I have no doubt that those students will be coding in a month.

Just like learning to ride a bike doesn't mean BMX competitions, it's still a step that could lead people to anything they want to make of it. I'd expect plenty of options for next steps, including learning to do ticks on a BMX style bike. The key is that not all of these next steps are serious endeavors. Some people learn just be be enlightened.

I do hope it inspires students to take steps to learn more. We'll see how it goes and we'll also see what students think after taking the course.

I banged out a YouTube clone with user registration and voting for an intranet in less than a month after knowing nothing about Rails using the exact methods the author is talking about.

Sure it was no showcase example of Rails development but it works and people love it (it's been a few year now and to be honest, I've only made minor changes since).

Edit: I did have years of programming experience beforehand, but not in a language like Ruby or a framework like Rails. It was at times, mind-bending. I think the key difficulty was combating presumptions.

You mention not knowing Ruby before. But did you already know how to code?

When you can already code, picking up a new set of tools is a whole different beast to learning how to code from scratch.

Okay, learning Rails with years of programming experience under your belt is in no way comparable to learning how to program (hate "code" as a verb) from scratch. Even if all you ever did was write device drivers in MIPS assembly, you're at a huge advantage over someone who has to wrap their head around what the heck a while loop or an assignment statement is.