What age can I start teaching my kid programming?

My son started coding with the coding puzzle app Lightbot Jr when he was 5. I think kids as young as 3 or 4 can learn programming without screen time. This is known as tangible programming. The basic idea is for the programming interface to take the form of objects in the physical world. Commanding a human being to move left, right, pick up object is probably the simplest form of tangible programming.