CDS is a Common Defence Service Examination which is conducted by the UPSC (Union Public Service Commission) twice in a year to recruit candidates to fill the vacant posts of Indian Military Academy, Indian Naval Academy, Officers Training Academy, and Indian Air Force Academy. This dream job in defense is aspired by many across the country. CDS Exam Pattern: It comprises of two stages: 1. Written Exam 2. Interview for intelligence and personality test Exam Pattern- For Indian Military, Indian Naval and Air Force Academy. English, General Knowledge and Elementary Mathematics (100 marks and duration is 2 hours) for each. For Officers’ Training Academy: English and General Knowledge( (100 marks and duration is 2 hours) for each.