Mailgun Technologies interview questions

It was a very long interview process. First meeting was with the technical recruiter. 11 days later, I met with the hiring manager. I got very positive feedback on the hiring manager interview about a week later and was given an assessment assignment to complete. See assignment ask in the interview question section. A week later, they told me I passed the assessment and scheduled a day of meetings with different team members. The last meeting was a review of my work history from high school to present day and then I presented my assessment presentation. About 1 1/2 weeks later, I met with the CPO which was to be the last meeting. The CPO joined the call late and complained that he was having a bad day. Said he didn't know why he was meeting with me. Later in the interview, he said that the hiring manager wasn't on the same page with him. A week later, I was told that I didn't get the job. The interview process took 1 1/2 months from start to finish.