Debug performance issues

# Enable debugger
php7.2 bin/magento config:set --lock dev/debug/debug_logging 1
php7.2 bin/magento dev:profiler:enable html

# Disable cache
php7.2 bin/magento cache:disable
php7.2 bin/magento cache:flush
service php7.2-fpm restart

# Enable DB profiler
vi app/etc/env.php
https://devdocs.magento.com/guides/v2.3/config-guide/db-profiler/db-profiler.html