Not every web app is high-scale, constant load. Many are ultra-low load and can do DB migrations by simply warning users about anticipated downtime. I've worke

Not every web app is high-scale, constant load. Many are ultra-low load and can do DB migrations by simply warning users about anticipated downtime. I've worked in both environments. It's about understanding your business needs; "cloud" can quickly turn into premature optimization and burn time/money if you don't need it.