One month after submitting my application materials, I received an invitation to interview at the agency. I met with project three managers who preceded to ask me targeted questions about specific work experiences relevant to the job description (competence with specific computer programs, project management abilities, etc) The managers were conversational and relaxed, qualities that put me at ease and allowed me to perform my best as an interviewee.
I suggest bringing a portfolio of relevant work, be in examples of written communication or design work.