Production notes for a PHP 8.2 migration

A PHP runtime upgrade should begin with production-shaped traffic and dependency evidence, not with the absence of syntax errors on a development workstation.

Make deprecations visible

Run the application and representative background jobs on the new runtime with deprecation reporting collected outside the user response. Dynamic properties and changed internal behaviours often appear in older libraries before they appear in application code.

Verify the complete runtime

Compare enabled extensions, INI values, locale, timezone, process manager settings and memory limits between old and new pools. Rebuild native extensions and confirm that image, database and queue clients use supported versions.

Use parallel release pools

Send a controlled proportion of replayed or production traffic to PHP 8.2 workers, compare errors and latency, then expand gradually. Retain an explicit rollback to the previous pool without sharing incompatible cache or session serialisation.