The very next day after I sent in my application, I was given a cognitive assessment, which was essentially 5 mini-games that tested how well you solve various problems in limited time.
After that, I was sent a Hackerrank coding assessment on the same day, with 3 coding questions to be solved in 3 hours. The questions were similar in difficulty to the Easy and Medium questions on Leetcode. I was able to pass all test cases in around 90 minutes, which IBM even said was the average completion time among applicants. I then received an email saying that my coding assessment has been received, and I will be under consideration for the next steps.
However, I logged onto the career portal a couple days later, and found that my application was no longer under consideration, with no explanation or feedback. Never received a rejection email, and never spoke to a single person working with the company.
Based on a recent review I've seen here, I assume the position had already been filled, so I'm quite frustrated that I just wasted my time with this process. The only good to come out of this is that my assessment results are valid for the next 12 months, so I guess I'll save time for the next application, whenever that will be.