List experience that relates to the qualifications as required on the job announcement. How to fill out the Contra Costa County Employment Application Form?1. Read the instructions carefully. 2. Fill out the pdf form online, download the pdf and email the filled out form with your resume to the email listed on the job posting. Applicants claiming these credentials will be required to provide proof as a part of the screening process. Contra Costa County only accepts online applications. When viewing a job posting for a currently open examination, you can select the option that says 'Apply'. Welcome to Contra Costa County's on-line application process! Become an interesting person. It's a hell of a lot more fun, and it's a hell of a lot more useful after you finish high school.