When deploying infrastructure with CloudFormation, at some point you will reach a moment when your CloudFormation JSON or YAML file is just too big. It will be too long to get a good overview of what’s in it, manage parameters and all dependencies between resources within the template. Nested stacks may be a solution, but if sometimes you can’t/won’t/don’t use them for whatever reason (for example, it will get to complicated to manage tested stacks or their contents are not reusable between other stacks).
Even if you’re using troposphere to generate your templates, you’ll face the same issue – a very long Python file. Luckily, if you are using troposphere, you’re inherently using Python – which means you can take advantage of it.