Good developer is an artist, a craftsman who enjoys the process of creation. Bad developer considers himself as a programmer, responsible for generating lines of code.
Good developer understands the problems of the customers. Bad developer understands only the technical problem at hand. Good developer does not define the why, but constantly strives to understand why. He’s responsible for the how, and still sees the big picture. Bad developer is focused on building classes and methods and configuration files, but does not get the big picture.
Good developer understands the complete architecture of the product. Bad developer knows only the components he’s written. Good developer fully understands the technologies that are used within the product. He understands what they are used for, and how they work internally.
Good developer is not afraid of new technologies but embraces them by quickly getting a grip. Bad developer only sticks to what he knows. His immediate reaction to any technical change is negative.
Good developer is constantly learning and improving his skills. Good developer reads technical articles, and finishes several technical books a year. Bad developer does not have time to learn. He’s always too busy with other stuff.
Good developer cares about the product quality. He is also very much concerned with the process quality. Good developer pushes himself to create bug-free code; bad developer leaves it to QA to find bugs to fix.
Good developer develops features which create value for customers. Bad developer completes tasks. Good developer will never claim the requirements are incomplete, and will make sure to fully understand the features he’s working on. Bad developer will wait until the finest details are available. To emphasize: good developer is the CEO of the feature – he’s going to make sure he always has the information needed to accomplish the feature, and in case information is missing he’ll make sure he gets it.
Good developer is not afraid to go into anyone’s code. Bad developer is afraid of others looking into his. Good developer understands that it shouldn’t take more time to write self-explanatory and well-documented code. Bad developer always needs to allocate extra time to document and simplify.
Good developer will never feel his code is good enough, and will always continue to clean and fix. Good developer always strives to create elegant solutions but understands that his job is to deliver value to customers. Bad developer thinks only about the elegance of his code and leave the job of delivering value to others.