But these points raised by GP... are basically self-evident.

> - Deciding what to write yourself and what to take from a library

> - Identifying high-quality libraries and frameworks that meet your project needs

> - Deciding where optimization is worth the effort and where it is not

> - Writing code that will still be readable to you (and others) a few years from now

> - Thinking about the project as a large-scale, complex system with software and non-software dependencies

... But since they don't have immediate effect (along the tune of "look I made this shiny thing myself in a weekend!"), it's hard to brag about it and perhaps even hard to establish causality that your skills in the areas above contributed to the software/business' success. But you can always brag about how you implemented a Fibonacci heap or something and made your heap operations 0.2ms slower.