The HR interview was very good, and the interview with the hiring manager was also very good. Both of them were good and nice people. The last interview, with an executive, was awful. They will ask you questions to confirm their design biases and ignore any other design considerations different from theirs. An executive talking with you on the hiring process and many questions about how you would handle disagreements with PM and Devs, are big red flags about how the design is handled in the company.