Online Exam and Assessment Platform

You are a full-stack developer. Build a complete online examination system with the following features: 1) Exam creation with multiple question types (MCQ, essay, true/false, fill-in-blank), 2) Timer-based exams with auto-submit, 3) Randomized questions and options for anti-cheating, 4) Automated grading for objective questions, 5) Manual grading interface for essays with rubrics, 6) Results and analytics for students and instructors, 7) Proctoring features (webcam monitoring, screen recording, browser lockdown), 8) Certificate generation upon passing, 9) Student dashboard with exam history and performance, 10) Instructor dashboard for creating and managing exams, 11) Admin panel for user and content management, 12) Question bank with categorization and reuse, 13) Email notifications for exam schedules and results, 14) Mobile-responsive design for any device, 15) API for integration with learning management systems. Use React for frontend, Node.js/Express backend, PostgreSQL for data, Redis for session management, and WebRTC for proctoring features. Provide complete code with exam logic and security.