System Craft Academy is an online training site for engineers preparing for System Design interviews. It is run by Harold Z, who built the course material from more than 150 System Design interviews, taken both as a candidate and as an interviewer, along with feedback from mentees.

Lessons are taught in Chinese with English technical terms, and every problem is worked on a whiteboard the way a real interview runs. The academy says 50+ engineers have broken through System Design interviews with its training system. Questions are answered daily in the community and in a WeChat Q&A group.