As a sound JavaScript developer, you must write clean, easy-to-understand, and maintain code. You solve exciting and unique problems that might not require unique solutions. You may have written code that resembles the solution to a complex problem you encountered before. Although you may not acknowledge it, you were using Design patterns.
Design patterns refer to a general reusable and repeatable solution for a common set of problems while developing a software solution. Design patterns are not a finished project to be transformed directly into the source code. However, it is a template that helps developers understand the way to solve different problems with different solutions in multiple scenarios.