http://localhost:3000 http://localhost:3000/oop http://localhost:3000/solid http://localhost:3000/srp http://localhost:3000/ocp http://localhost:3000/lsp http://localhost:3000/isp http://localhost:3000/dip http://localhost:3000/design-patterns http://localhost:3000/creational http://localhost:3000/factory-method http://localhost:3000/abstract-factory http://localhost:3000/prototype http://localhost:3000/builder http://localhost:3000/singleton http://localhost:3000/structural http://localhost:3000/composite