Design your architecture for the acceptable downtime. We all want 0 downtime, but it happens. You really need to understand what you are building for. Calculate

Design your architecture for the acceptable downtime. We all want 0 downtime, but it happens. You really need to understand what you are building for. Calculate the time of downtime you are fine with. for 99.5% it is >3h but for 99.9 it is 43m. and 99.95 it goes down to 20m per month. So the less time you have allowed, the less time you have to react to a problem. So how long will it take you to turn on your pc on a weekend and try to figure out what is the source of downtime? so if you plan to go above 99.95 things will really get tough, and you will have to do major restructuring to reach this, as you cant allow failures. So If you need 98% or 99.99% availability, your design will be very different. When you start designing for >99.97% stuff will get complicated.