Low level design mock.

Hi Everyone, I am having almost 12 plus years of experience and have solved almost 700 plus leetcode problems. I mostly clear DS round for all major companies but every time screw up in low level design. I have read through edecutive.io course and gone through major YouTube low level design channel but still I screw up everytime in a real interview. Currently I am not sure how should I improve and it would be really helpful if you can guys training course with mentor low level design. I am fine with paid mock also. #swe #engineering #software