Technically I learned to enjoy Object Oriented Programming again. Before I got into BTCPay I was doing mostly Functional Programming and thought I wouldn't go back to OOP, but C# is a nice language once you get used to it.

Other than that the best thing about BTCPay is the people I got to know and became friends with. It's surprising what a team can achieve, when everyone is so passionate and motivated — something you don't see that much in the corporate world.