Question How does unity load scenes under the hood?

How does scene loading work on unity, when u call SceneManager.LoadScene?


I've been struggling with scene loading performance recently(on android a basic scene, like a settings scene with no 3D models or images, can take up to 3 seconds to load), so I started to wonder how do scene loading works under the hood?

Does unity do it in a smart way, like for example loading all visual assets of said scene in parallel first(to maximize disk usage and thus lower the time it takes), then object data and scripts or does it load all things one by one without parallelization?