The best thing about the giac machine learning engineer mock tests that i liked was that the practice tests have equal weightage of all the topics just like the actual exam. This helped me get enough practice that was required to clear the concepts i had about the topics, neural networks and supervised learning. The simulated practice tests are a must to clear the exam in an organised fashion i think.
GMLE Syllabus
Use this quick start guide to collect all the information about GIAC GMLE Certification exam. This study guide provides a list of objectives and resources that will help you prepare for items on the GIAC Machine Learning Engineer (GMLE) exam. The Sample Questions will help you identify the type and difficulty level of the questions and the Practice Exams will make you familiar with the format and environment of an exam. You should refer this guide carefully before attempting your actual GIAC Machine Learning Engineer (GMLE) certification exam.