The third part of the book will cover topics that concern any desktop application developer, but here they are dealt with in the context of programming Cocoa apps for macOS.

Some of these will seem more appealing than others. There are many topics in the early stages of learning to program that are (or perhaps just seem to be) less important and/or exciting, such as just writing a few pages full of code and hitting the Run button; but these things later become an essential and rewarding part of what we do as developers. As one moves from working on relatively small and simple projects, usually as a sole coder, to working on larger, more complex, and longer-term projects, frequently as part of a team of both devs and management staff, there is a profound change in priorities, as code clarity, code re-use, integration, documentation, and communication become major aspects of our work.

There are also fascinating challenges around dealing with some of the unpredictable aspects of software that needs to integrate itself successfully with a digital universe lying outside our app and beyond our control, particularly with regard to the Internet, as our code will need to deal robustly, efficiently, and gracefully with whatever comes back at it across the network.

Producing high-quality code, while working quickly and communicating effectively, is partly a matter of experience and partly a matter of knowing what tools are available to make the best use of the hours you spend coding, and which techniques to choose when designing the internal workings of your app.

These chapters will look at the challenges posed by asynchronous programming, error handling, debugging, and many other areas that are an indispensable part of producing software in a professional environment: on time, on budget, maintainable code. Which is basically what the industry needs from you.

And for which you will be handsomely paid. Just saying.