A content delivery network does one thing superbly: it puts your page and your video close to the reader, so the long part of the trip is short. Every serious site uses one, and they are right to.
Then comes the last hop. From the antenna to the phone, across a cell shared with a stadium, a train, a street. That hop loses data, and no amount of caching near the reader repairs what the reader never received. The page waits. The spinner turns. The session ends.
Whose problem it is
Not the CDN’s. Its job ends at the edge. Not the reader’s, although they are the one who leaves. It becomes the problem of whoever counts sessions: the newsroom that loses readers at prime time, the video service whose stalls climb on mobile, the shop whose checkout fails on the way home.
What Lagbuster does there
It keeps what the reader asked for arriving over that last hop when the network is losing data. On the web, in early access, it is a snippet on the page and a plugin in the player: nothing changes in your CDN or on your servers, and you judge it on your own dashboard, one section at a time.
One limit, said plainly: the first visit of a new reader still travels over the normal network, because the snippet has to load once. From the second visit on, that reader is covered.
The CDN keeps doing its job. Lagbuster does the part nobody was doing.