Learning from ‘Working Effectively with Legacy Code’ by Michael C. Feathers
Working Effectively with Legacy Code by Michael C. Feathers is a classic software development text. Not only is it still completely relevant when working with code, seven years after it was published, but also the approaches it advocates at the source code level are becoming essential to apply at the component and system integration levels too as our software systems become more complicated and polyglot, and we learn to fully automate our deployments and treat our infrastructure as code.
For an overview of the book itself, read my review of ‘Legacy Code’ on Amazon.co.uk. I describe the different sections and how each is useful in a particular context. The rest of this article will focus on other aspects of Legacy Code, particularly the ‘why’ of changing code, and the implications for Continuous Delivery, infrastructure-as-code, and deployment automation.