Trying to shave off some time from boot of rpi zero w and main culprits are:
I know I need most of them so there is probably nothing to do, but what about:
keyboard-setup.service - I was googling around and could not find normal answer... is it needed when there is no keyboard attached ? ( only ssh )
raspi-config.service - What does it do, ,is it needed ?
ntp.service - Hmm I was thinking turning this off and have the time synced every 30 min by cron
avahi-daemon.service - I think this can be turned off, no need for zeroconf discovery on net