Supreme Court of The United States appointment. Presidents appoint a candidate they like, congress greenlights their ascent to the position.

Oh highly questionable, it's caused a lot of people to rethink the safety of lifetime appointments. But there are avenues to try, someone doesn't have to retire or die, the number of SCOTUS judges can be raised and then you can appoint new judges, but then so can the next party and so on so forth, or at least they tell us that the threat of 'the other side' packing the courts is too much of a danger for their own party to pack the courts

It is done on both sides, except both sides haven't had an equal chance to make appointments due to life span of existing judges and the then Senate Majority Leader (senator who is appointed the head of that ruling body when their party takes a majority in that body) in 2008 blocked all Supreme Court appointments that came up for all 8 years of the Obama administration. That was Mitch McConnell, and he, and his party, blocked appointment of new judges by just never allowing the motion to be voted on, as the Republicans held the senate 2 years into Obama presidency (when some seats opened) and as such their majority leader gets to decide the docket of what will be voted on in the senate and he chose to never once allowed SCOTUS appointee motions to reach the floor.