GroupSync automatically syncs your groups between Google and Slack. Tag @support-team on Slack and rest assured that emails to support-team@yourcompany.com will reach the same people.

I lead a large team at my day job where we use Slack and Gmail for collaboration and communication. I frequently need to add/remove people to groups when team membership changes, and I got tired of doing this in both Slack and Gmail so I created an app to automate this. Hopefully this is useful to other people! I also tried to make the pricing as simple and transparent as possible. If you make no changes to your groups, you pay $0. If you make changes to your groups, you pay per user synced. And users synced between multiple groups are only charged for once.

Thank you for this approach - Can solve some problems for teams using these 2 platforms

Going to give this a try, team GroupSync. Looks interesting.