It's a 5 step test, you might retake one or two steps depending how much they like you and how you failed. I had a problem with my tooling doing a live coding test, could take it again within a month. Others have been told to be sure to apply again in a year. Some haven't been invited back. Speaking English at a pretty good level (not accent free per sé but you should be able to get a complex technical point across) is required.
Another problem is that most people don't use basic algorithms too much in their daily jobs, for example because collections are too small to feel the difference or because you kind of "feel" what is the optimal way to do things but you can't just whip out an optimal pathfinding algorithm under pressure. This requires some training.
But their process is a bit difficult, as another sibling comment has described. Knowledge of algorithms is required. And the second stage of being able to clear a programming test, is generally described as a significant barrier. It is advisable to practice algorithm problems before applying.