They have a very interesting OA including a lot of different topics, like regular expression, SQL, coding and data structure questions, I think it is pretty hard, I enjoyed doing it tho.

Great start with clear communication on who would be interviewing and the type of interview. I was treated well at every video interaction. Very little time was spent asking me about my multi-year extremely applicable background. It was unclear what the role desired in practice as the hiring manager had two teams and seemed to be optimistically hiring for either one, but not directly for one. After a lengthy 6-week interviewing process, I was kept on the hook for another 6 weeks saying they needed another week one week at a time to review all candidates. After never getting a response, but probing again after the recruiter-communicated "get back to you by" time had elapsed, I felt quite demoralized by the process. In the end, after one of these yet-again missed communication deadlines I received an automated email from greenhouse saying no. I expected it, but after giving so much time meeting several directors including making it to the final interview, the degree of disrespect to my application was shocking.