Most job applications request a pdf portfolio, typically under 5mb. Personally, I think it definitely helps to have a website as well, maybe not specifically for a job application, but just to enhance your overall online presence. It’s much easier for me to give my card to someone when I meet them with my url on it, than exchange e-mail addresses and ultimately mail a large portfolio. I think coroflot is fairly ubiquitous among designers, but I don’t think many apply for work with their coroflot pages. Doesn’t really enable you to present your work in the manner you want in order to translate the experience you’re looking to convey!