Unity FPS Prototype Development

Looking for an experienced Unity game developer to create a custom first-person character controller. Requirements: First-person controller (FPS). No Rigidbody or Unity physics for movement. Movement should be fully custom and code-driven for maximum performance. Support for walking, running, jumping, crouching, slopes, and stairs. Clean and scalable architecture suitable for future expansion. Easy integration of additional mechanics later (inventory, weapons, interaction system, multiplayer, etc.). Optimized for large scenes and mobile devices. Well-structured and documented code. The goal is to create a solid foundation that can be used as the core controller for a larger game project. Please provide examples of similar controllers or FPS projects you have worked on.