This is a new forum that's focused on supporting managers in tech and building high performing teams. I've tried out the alpha and found it quite helpful as an engineering manager. <a href="https://risingteam.com/" rel="nofollow">https://risingteam.com/</a>
Not exactly what you are asking for but <a href="https://leaddev.com/" rel="nofollow">https://leaddev.com/</a> and their slack channel are very good.