I would say this company is a waste of time. I was a bit put off initially when told how many stages there would be. I gave them the benefit of the doubt that this would be for thoroughness, Unfortunately it was not.
The first interview was fine. The second interview (technical) also fine. However I was rejected there. After chasing up for feedback, since zero reason was given, I was told that basically it was because I wrote some code for a custom hook, thought out loud "why doesn't the function inside run?" , and since my interviewer answered immediately "you need to call it, in an effect", this indicated I didn't know about useEffects. Forget the fact that I've been a principle code owner on a react codebase for the past 2 years. Thinking out loud "what did I miss" for half a second was interpreted as not knowing these concepts. It did not matter that once the word "effect" was mentioned, I added the code immediately and then explained why it's needed.
The interviewer didn't ask any questions about choices I had made. No questions about my thinking process. At the time I thought that was fine; I guessed we were seeing that I can code react. It felt like a fairly normal pair programming task. In my experience, the point of these tasks should not be "always write everything absolutely perfectly" but more about the thinking, the ability to work through a problem, take in suggestions from others, work collaboratively.
In my time I've seen many very great developers do something trivial like write a function, forget to call it, and wonder for a second or two why their code isn't running. I've never interpreted that to mean they didn't know what they were doing.
It's frustrating to be rejected for something so random after spending time preparing.