I had an interview and I can't well answer that question [closed]

I'm a student in master's degree "data science", I often go to job interviews, generally I do them well, but recently a recruiter asked me a question that I felt I didn't answer well, the question was: how you test a code you develop? I tried to answer by mentionning the different precision tests, I felt that I gave a wronfg answer, I didn't know If I have to answer from the developer or data science point of view.

Thank you in advance for your answers