One Concern Machine Learning Engineer interview questions

Applied online through LinkedIn. Got a reply from HR that they want to move forward. After a brief call with HR they have sent me a coding challenge. A dummy imbalanced dataset is given and task is to perform multi class classification under some conditions. Once the challenge is submitted, they have scheduled a video call with their Data scientists to debrief about the challenge. They were clueless when I asked them about their tools and technologies. After 3 weeks I received a reject.