China's Gaokao (National College Entrance Examination) is considered one of the world's toughest exams, determining admission to top Chinese colleges.
India's Joint Entrance Exam (JEE) for engineering is highly competitive, comprising the JEE-Main and JEE-Advanced.
The Union Public Service Commission (UPSC) exam recruits Group "A" officers for prestigious roles in the Indian government.
Mensa, a global high-IQ group, admits members scoring in the top 2% of IQ tests worldwide.
The Graduate Record Examinations (GRE) are vital for graduate program admissions in the US and Canada.
The Chartered Financial Analyst (CFA) Program's three-part exam is renowned for its difficulty.
Cisco's CCIE certification exam, a technical test, is challenging in the field of networking.