Sigma Computing Operations interview questions

Applied online, got an email from the hiring manager to schedule an interview (not sure if they have a formal recruiting team). That went well so he sent me a(n unfriendly) email the following week to schedule another interview with him to go deeper on my background. The interview was a little odd, mostly hypothetical questions and the HM wasn't super engaged or friendly / seemed a little distressed in general. I left feeling like it went incredibly poorly. Got an auto rejection email from a no reply email address two weeks later, which felt cowardly and impersonal given I had done two interviews. Based on the reviews of the company, not sure I'd bother.