You have your app state in an object/class, and components automatically rerender when the part of the store changes that they access during render.

    class Store {
      counter = 0
      constructor() { makeAutoObservable(this) }
      increment() { this.counter++ }
    }

    const Component = observer(() {
     const store = useStore()
     const click = () => store.increment())
     return <button onClick={click}>{store.counter}</button>
    })