Ask HN: How do you find the optimal EC2/Azure instance type for your workload?

I'm looking into performance differences between cloud instances. Now there's the usual benchmarks and frameworks, some also specifically geared towards cloud e.g. PerfKit benchmarker [0].

I'm more interested in automating performance testing of my custom workload (say a web application deployed as a docker container). Are there any tools that you can just give your AWS/Azure credentials and it will deploy your container to various machine types, run some tests and collect the results? What are you using for finding the optimal machine type and vertical vs. horizontal scale for your applications?

[0]: http://googlecloudplatform.github.io/PerfKitBenchmarker/