Yes, it does. Bad architectural and engineering practices will start to burn you at a couple thousand lines of code. "Maintainability" isn't some far-off property that begins to matter when you're at hundreds of thousands of lines.<p>For the record, the best way to learn software architecture (what works, what doesn't) is to maintain your own code. Only when you support a project from inception to maturity do you get a sense of <i>how much</i> architecture matters and <i>why</i> it is so important.