http://abp.io/ http://abp.io/ is probably the best open source one I've seen. They also offer a paid product which is fairly comprehensive. I don't quite like t

http://abp.io/ http://abp.io/ is probably the best open source one I've seen. They also offer a paid product which is fairly comprehensive. I don't quite like their frontend stuff but the backend side of things is definitely what you're looking for. There are plenty of paid products in every language which are basically B2B SaaS templates. ABP, bullettrain, Laravel etc.