Onshape interview questions

It was actually a nice round of interviews up until I got to the third round. The person conducting the interview just seemed over it from the beginning. When I asked the question if they had any concerns, the response was - everyone seems to be asking that question lately - which was a disappointing response to get. When I asked for feedback, I got zero and was ghosted after several attempts.

They use whiteboard and paper to write code. They do not focus too much on Data structure and Algorithms like big tech, they focus on implementation details. First will be an easy phone interview, then they ask specific problems like Front end and back end and ood and java knowledge, I will not tell the exact problem but they are tricky for me.