This is the 884th most frequent Japanese word.
以来
"以来" means "since" or "ever since."
以来 indicates that the action of achieving successes is ongoing from the moment the subject started working at the company.
この会社で働き始めて以来、多くの成功を収めてきました。
Since starting to work at this company, I have achieved many successes.
以来 shows that the act of living abroad has been uninterrupted since graduation.
大学を卒業して以来、彼はずっと海外に住んでいる。
Since graduating from university, he has been living abroad continuously.
以来 is used here to imply a starting point from which an ongoing event or condition continues.