A detailed dive into data structures and algorithms (C or C++ preferred). The interviewer helped me out whenever I got stuck with the problem. After that, there was a general discussion about the projects I have worked on by the Data Science team. And it finally ended by testing me on machine learning algorithms and real-life case study.

Invited for interview from a hackathon where I was the runners up. Called for Interview, directly by the CTO. Asked some basic questions, and while talking to him about machine learning , I got to know he had limited knowledge about the subject. He got impressed with me. Later, I was given a simple task which I did easily. But then they didn't contact me for several days. Once asked about the result I was told I am selected for this round(They told me last time that was my last interview, and would join if I completed the assignment given after). I was called again to office as they had doubt if I knew Data Structures and Algorithms or not. I went there, and then they gave me a problem. I made the solution but then they raised some further doubt and kept on asking unnecessary questions. Finally, I was told to cover Data Structures, and come again for interview in future, and I would definitely get selected.