Software developers should design the structure like you are going to leave today. It doesn't mean to write document all the day. For management purpose, elaborative work note helps clear responsibility and progress. User manual or technical documentation is better left aside before the development gets stable. Make sure your design could be altered by merely change some settings, and then the user or next developer could continue their work on same environment or migrated site. Take computer games as example. The project manager or another developer could change score calculation by altering numbers. Or they can change the entire visual style and drawing by change folder name. Take website as example, by changing settings, the user could change database, change relative paths over entire site, change the levels of access privilege, change the loader for different types of resources, etc. Loyal to your profession.Design the s...