Employers post positions specifically for Darden alumni. You can save a search and set a Job Alert so that you are notified by e-mail whenever a new job that meets your search criteria is posted.
Alumni can enter their profiles/resumes into a database for which access is marketed (by MBAFocus) to top MBA employers. Once your resume is in the system, you may also search jobs posted by those employers.
The online resource for UVA alumni includes a job board that can be searched for keyword (including "MBA")...there are opportunities there that do not make it to the Darden job board. To access HoosOnline, you'll need to register which requires UVA alumni status verification and can take a day or so to process.