Cerebrae interview questions

Met with the HR person who is also an engineer and he also gave me a tech phone screen we shared a screen. He gave me a problem where you use a list of lists to solve it. I then met an engineer for an in person, I guess behavioral but was more of a casual talk. I then went in their shared office space for a 2 hour interview. First interview was coding and you are to solve another problem where you parse some text and do a calculation. System design interview was around what they said was security but seemed to more go around data modeling I was given a blank screen where I guess I could type out just simple things. Salary was never mentioned, which was curious. They never asked me salary expectation and I didn't ask them either. They are a very small operation .