Something similar to https://lunch.pink but specific for work, so running in a container with OIDC setup for coworkers.  Coworker then could create a lunch event public or private, invite folks, folks could respond with interest and vote for their favorite restaurants, or just keep their same favorite restaurants from last time.

As a webapi could create integrations into Teams or a mobile app.

Could be a good excuse to write a controller and some custom resource definitions.  Some initial ideas captured:

---
New-Restaurant

  Add new restaurant to favorites list
 
Get-Restaurant

  Get listing of preferred restaurants

Set-Restaurant

  Enable/disable restaurant as favorite to include with voting
 
Remove-Restaurant

  Remove restaurant from favorites list

---
New-Event

  Create new event
  -Description ""
  -IsViewable <true>
  -IsInviteOnly <false>
  -Timeout <when_voting_ends, default 5 minutes>

Get-Event

  Show all events if admin, otherwise only show public events, or events you've been invited to

Set-Event

  Adjust attributes 'IsViewable', 'IsInviteOnly', and reopen voting.

Remove-Event

  Remove event

---
New-Invite

  Create new invitation to event
  - only owner can create invitation
  - invite id is a guid

  -Username <username> // <optional> send through teams, or email, etc...
  -EventId

Get-Invite

  View current/expired invitations

Set-Invite

  Accept / Reject an invitation

Remove-Invite

  Withdrawl an invite