Can you please help me to enhance the below experience certificate:
28th February, 2019
To Whomsoever It May Concern,
This is to certify that <<Full Name>> has served as a full-time employee at <<Company Name>>, for the period between <<Start Date>> to <<End Date>>.
<<Full Name>> started working in the company as a <<Starting Job>> and with his sincere efforts and excellent performance, he was promoted to the current position of <<New Job>>.
During his tenure, we found him to be sincere and hardworking, he demonstrated as a diligent and truthful employee. His interpersonal skills are outstanding, his services were found to be satisfactory and professionally excellent by his managers.
He was a productive employee we valued, and we wish him all the best in his future endeavors.
Yours sincerely, 28th February 2019 From Saudi Arabia, Riyadh