We generally get involved after and employer has done their own recruitment, initial screenings of applicant resumes, and at least one phone screening and/or in-person interview.
We recommend they do those first because the employer is in the best position to decide which candidates are an initial match based both on their relevant employment experience and how well they establish rapport with the interviewers.
After the employer establishes there is a good match, we begin our part of the process. At the end of any of our assessments, the hiring company gets a written summary of our findings and follow-up by phone as needed.