Seeking Unity tutorials on architecture and scalable code practices

[EdwardZW]

I'm a beginner learning Unity with the goal of creating simple 2D mobile games, but I'm struggling to find tutorials that go beyond basic movement scripts and actually explain game architecture and scalable code practices. Many tutorials I've found show how to do a specific thing but don't explain why it's done that way, leaving me unable to adapt the concepts to my own projects. For developers who are self-taught, what tutorial series or learning resources did you find most valuable for understanding core Unity systems like ScriptableObjects, event-driven design, and building a maintainable project structure from the ground up?