At my previous company we built our own CDN because we were streaming video to a long tail of global users for a limited library. The problem with off-the-shel

At my previous company we built our own CDN because we were streaming video to a long tail of global users for a limited library. The problem with off-the-shelf CDNs was they couldn't keep our content cached for the long tail, but for the same price we could replicate our limited library to bare metal. Traditional caching could then go on top of that. This was a huge win for QoS on cache misses, which were a significant portion of our traffic. There are tons of tradeoffs to make this happen which is why we couldn't find an off-the-shelf solution to deliver the same results.