Not all application resource demands fit nicely inside instance types.<p>Once you determine your application needs, you can set your cpu&#x2F;memory resource needs per container&#x2F;service. Then you can run these containers inside your fleet more smartly.<p>This really comes into play for memory and cpu ratio. Look at the price difference between:<p>one m4.2xlarge = 32gb mem, 8 cores = $350 a month<p>eight t2 medium = 32gb memory, 8 cores = $300 a month<p>You get twice as much compute for less money with the ability to mix and match service needs instead of being constrained to individual instances.