Do you really find function overhead to be that great of an impact on performance? I work on a php app that sees around 15k/rps and I use a lot of functional pa

Do you really find function overhead to be that great of an impact on performance? I work on a php app that sees around 15k/rps and I use a lot of functional patterns (feels best to me, my brain was formed in a lispy way). By far database time remains our biggest bottleneck, especially since we finally made it onto PHP7