Performance Chat Summary: 7 October 2025

The full chat log is available beginning here on Slack.

WordPress Performance Trac tickets @westonruter mentioned ticket #63636 related to BFCache was punted due to an unresolved Chromium bug around Clear-Site-Data: “cache” headers. @westonruter identified ticket #43258 on output buffering as the current biggest blocker. He explained that while there’s been significant discussion both on the PR #8412 and in Slack, the debate centers around the trade-offs between enabling full-page buffering (to allow post-render optimization) versus keeping the door open for streaming, which could improve initial load performance. He provided further context on how classic themes already stream via procedural