Create levels from json file configuration

I have more than 60 json files that I want to read and create levels from. Each file describes the position and dimension of boxes and spheres, how can I create levels from these? This would be a one-time operation since we are migrating from a custom engine to Unreal. Is this possible? I don’t want to recreate each and every level as it would take a lot of time. I’m ok with writing some script in c++/c#/python/js/etc.