The phrase "documented success" refers to having evidence or proof of achievements or accomplishments. It means that someone's success or progress has been recorded or verified in a clear and reliable way. Full definition
A highly dedicated individual and a proven leader with documented success in progressively dynamic and challenging positions, with proven ability to work effectively in busy environments with positive results. (resumemycareer.com)
• Highly motivated and compassionate caregiver with documented success in providing individual personal care to clients by employing expertise in psychological management and physical care. (coverlettersandresume.com)
As in work experience section, everything is in achievements and documented success of your activities. (epiccv.com)