Slack and Company interview questions

Such a long tedious process, 2 interviews 2 hours each. The 1st interview I met with 4 different people then the 2nd interview I met with 3 of the same people from the first interview in addition to the CEO. In the first interview I met with four people separate and the 2nd interview it was 2 interviewing me at the same time and the second half 2 interviewing me at the same time. I was initially contacted by HR for a phone screen, did the 1st interview within the same week then a week later contacted again to do the 2nd interview. After the 2nd interview never heard back from anyone and I sent thank you letters. Such a waste of time! They could've at least sent a rejection note since I used my personal time for the 2 long interviews. Don't apply here!