Senior Computer Vision Engineer – 3D Spatial Calibration & Biomechanical Motion Analysis (Python)

We are seeking a high-level Computer Vision and Mathematical Modeling Engineer to completely overhaul and refactor the core tracking architecture of our sports performance platform, eTrack. Our app analyzes athletic tests—specifically Sprints, Countermovement Jumps (CMJ), and Drop Jumps—from high-speed smartphone videos (up to 240fps). The legacy backend relies on a primitive, rigid 2D pixel-grid comparison logic (comparing bounding box centers frame-by-frame). This approach is fundamentally broken as it fails under camera angle changes, lens parallax, and perspective distortion on the field. We need a professional who does not rely on pixel-matching shortcuts. Key Responsibilities & Architectural Requirements: 1. 3D Spatial Calibration & Homography: Implement space calibration (Perspective transformation / Homography matrix mapping) using fixed environmental markers (e.g., cones, hurdles, track lines). The system must project 2D camera coordinates into a normalized 3D World Coordinates System (meters/seconds) to ensure pitch-invariant and angle-invariant accuracy. 2. Digital Signal Processing (DSP) & Jitter Filtering: Treat raw tracking outputs (MediaPipe/YOLO Pose) as a continuous signal. You must implement advanced filtering (e.g., Butterworth low-pass filters or Kalman filters) to eliminate high-frequency landmark jitter, ensuring raw mathematical precision down to the millisecond. 3. Finite State Machine (FSM): Drive a robust, production-ready Python state machine to precisely detect biomechanical phase transitions (e.g., ground contact times, flight times, exact gate-crossing frames). 4. API Integration: Package this mathematical logic into a clean, lightweight, and optimized FastAPI backend designed to process videos efficiently without server crashes. Requirements: - Degree or strong background in Applied Mathematics, Robotics, Physics, or Computer Vision. - Proven track record of building human motion analysis or gait/running biomechanics software. - Master level with OpenCV, MediaPipe, NumPy, SciPy, and signal processing libraries. - Strictly individual freelancers or dedicated technical leads only. No generalist agencies, no front-men selling outsourced work.