Eleven per cent of a request spent in the autoloader, on a machine where the optimised classmap had not been generated.
$ composer dump-autoload --classmap-authoritative
# before: 412 stat() calls per request, PSR-4 resolution
# after: 0 — the map is complete and misses are fatal
# which is why --classmap-authoritative is a production
# flag only: a class generated at runtime will not be
# found, and that is the trade.The authoritative flag turns every autoload into an array lookup and makes anything outside the map unloadable, which is correct in production and breaks a test suite that generates classes. The deploy had been running plain dump-autoload since a script was rewritten in 2021, and nothing about the application behaved differently — it was just slower in a way spread thinly across everything.