Very unfortunate title choice for an otherwise interesting post that praises LiveView

Not quite the proper takeaway for all points:

1. Large payloads over PubSub by themselves are just fine. We actually broadcast entire ets tables of presence information when we replicate data for new nodes, so by itself this isn’t a problem

2. This is the key takeaway here. Publishing events at scale must consider downstream subscribers. In this case publishing the entire user list for any individual user change was the mistake, rather than deltas of joins/leaves (or presence)

3. We won’t send anything on the wire if there is an empty diff, so I’d need to know more about this particular case.

Fail your way to success

TL;DR for those who haven’t read the well written article yet:

1. Avoid large payloads in Phoenix.PubSub if possible
2. Throttle PubSub events at the sender level to avoid clogged process inboxes
3. Using assign/3 in LiveView always causes an update via Websocket, even if no changes were made