Backend & systems·Scaling and load management
the instance count goes up on its own when CPU crosses a threshold, and back down twenty minutes after the spike ends.
Autoscaling
Adjusting capacity automatically from a signal such as utilisation or queue depth. It saves money on variable load and absorbs gradual growth. It is not fast: instances take time to start and warm, so autoscaling handles trends, not step changes — for those you need headroom or a queue.