[r1ch]

Loss-based TCP congestion control and especially slow start are a relic from the 80s when the internet was a few dialup links and collapsed due to retransmissions. If an ISP's links can't handle a 50 KB burst of traffic then they need to upgrade them. Expecting congestion should be an exception, not the default.

Disabling slow start and using BBR congestion control (which doesn't rely on packet loss as a congestion signal) makes a world of difference for TCP throughput.

[notpushkin]

Slow start could be a great motivator for battling website obesity though. If we could give people an easy win here (get your page size down to 300 kb and it will load in one roundtrip), I think more frontend devs would be thinking about it. (Not much more, though – most still won’t care, probably.)