How to measure and optimize DNS influence on CDN performance?

I want to measure and optimize the DNS & TSL costs on CDN performance. The current setup: Mobile app requests file from URL https://file.mydomain.site/file.jpg Provider A (in Germany) has a CNAME entry for file.mydomain.site pointing to CDN provider at mydomain.cdnprovider.net If CDN Provider has a CDN cache hit, the file is served at the CDN…