Can I ask what you ran into? I'm thinking about starting a side project with .Net Core for my API and React for my front end. I'm wondering if it's even worth it to use Core at this point or switch to Go or Node.
I was always partial to Pythons Flask as well
What did we run into? Tons of brokenness. Inability to use C# libs was the biggest problem, if you're trying to make anything significant you're going to have to roll your own everything. Java is the safest bet for large projects, I've never run into any issues finding a quality library to do anything. This is coming from a guy that's been a career C# dev for years and wishes he could defect to Java.