Interview with a senior developer. Started OK but he felt the need to barge in a bit too much. Waved away solution proposal that later on said that was the proposal that he wanted. When he was asked why did he waved it at first he said "Maybe that was it, I didn't hear".

Implementing mentioning ("@username") and the data modeling for the notification of such username/group mention.

How to notify group and/or users while the comment with the mentions is published efficiently based on the said data modeling.