The maintainers are generally available in Slack at
https://cloud-native.slack.com/messages/flagger/ (obtain an invitation
at https://slack.cncf.io/).

In alphabetical order:

Sanskar Jaiswal, Independent <jaiswalsanskar078@gmail.com> (github: @aryan9600, slack: aryan9600)
Stefan Prodan, ControlPlane <stefan.prodan@gmail.com> (github: @stefanprodan, slack: stefanprodan)
Takeshi Yoneda, Tetrate <takeshi@tetrate.io> (github: @mathetake, slack: mathetake)