There were multiple rounds of interviews and one exercise to complete. I realize they were trying to be thorough and ensure that only the best candidate was selected.
There were red flags galore in the process.
Asking a candidate to provide free work for a live campaign is unethical. Pay the person for their time; you shouldn't have to be told this.
Leaving huge sections of responsibilities out of the job description and grilling the candidate on these skills is a huge red flag. We aren't always prepared to talk about everything. Do I have the experience? I do. Do I know your system or the current best practices? Maybe not.
Intricately detailed processes accompanying a huge cross-section of responsibilities but paying very little, even for a nonprofit, is a red flag.
Expecting perfection in the role is a red flag, as is not allowing time to learn the role.
I have sat on both sides of the interview table many, many times. This process was a mess. After the last round, I was absolutely not interested.