This talk presents the importance of Computer Vision and Deep learning techniques in making Magic Leap an effective spatial computing platform. The four fundamental modalities are introduced: head pose tracking, world reconstruction, eye tracking, and hand tracking; emphasizing on the two main general themes: Understanding the world (spatial localization, environment mapping) and Understanding user’s intent (eye, gaze, and hands). The talk will provide a deep dive into the main modalities along with key challenges and open problems. We will go over some technical challenges that our team of researchers and engineers are tacking to make computer vision work for see-through wearable Mixed Reality device. We will start with an overview of the past 5 years of development in inside-out pose estimation (Visual Inertial Odometry), scene reconstruction, eye tracking, and sensor calibration and then dive into the long list of technical challenges that are left to solve.