CodeSignal online assessment, which essentially involved 3-4 leetcode hard questions. Took some practice to get it but I would recommend to actually practice with LeetCode and then do the Code signal online assessment.

I completed 4 interview-style leetcodey questions as part of an initial screening test. I expect that the invitation to do the assessment on CodeSignal is automatically sent out when you apply. The first question was very easy and then got considerably harder. I imagine if you are in any way good at leetcode questions it should be a breeze