Hi there!
If you are into developing add-ins in Excel, this is the conference you should go to:
DevelopExcel
Develop Advanced Excel Extensions
This one-day conference will be held in London on Thursday October the 18th 2018. It will be held at the Microsoft Reactor (70 Wilson Street London EC2A 2DB).
A number of expert Excel developers will be presenting to you all there is to know for the Excel add-in developer!