alt Hacker NewsIt only looks super obvious in hindsight and the well explained blog post. when a team of 5 is tasked with getting a completely new DNS up at the scale and integrate well with cloudflare.
if you spend cycles on nitty gritty opinions like this time to market goes out further and further out. some napkin math, 130 gen13 servers cost "only" ~$2.6M. relative to the importance of the 1.1.1.1 and the market at the time. that is nothing to cloudflare.
this is not to say good system design does not matter. it very much does, but making that call at that time would've butchered the prodcut very much similar to google+, youtube etc.
This one also looks pretty obvious "in foresight" (using the same tools that existed back then. Maybe owner dedupe might be less obvious and require a bit of knowledge and probing into actual data, but for rw vs ro you are fine knowing nothing?) and you forgot the napkin math re. how much your precious "time to market" would have been delayed by.
It's also not nothing, otherwise it would never be optimized away now, but left as is. After all, wasting time on optimization delays "time to market" for other useful features.
I also don't get the reference to YouTube, it's a very successful product, how was it butchered by good system design???