People who competed at the International Mathematical Olympiad went on to very different lives. Some became mathematicians. Others write software, trade, start companies, or left all of it behind. Most of us lost track of each other the week the competition ended.
After IMO is a quiet place to find each other again: where people are now, what they are working on, what they are looking for, and what they can help with. When someone hears of a position, a grant, or a team that needs people, they can pass it on to the alumni it is meant for.
It is private. If you competed at the IMO, sign in with Google and ask to join, or have a member invite you.