At one of my past jobs, I trained 4 team members who joined as college graduates, and they took on important assignments in a relatively short time. I want to write this as an achievement in my resume used to apply to a leadership role.
Trained 4 newbies to become key contributors
obviously isn't "professional" to be written in a resume. I looked up thesaurus.com for synonyms but the words that I found (freshman, novice, rookie) suffer from the same problem.
What is a good "professional" synonym for newbie?
PS: This is beyond the scope of this question, but if there is a better wording to describe the above achievement (without being overly verbose or obscure), I would like to know it as well.