I know it's kind of cliché and in my last project it also wasn't soo bad, but Java is not something I associate with lean and nimble. I know, OP didn't ask for

I know it's kind of cliché and in my last project it also wasn't soo bad, but Java is not something I associate with lean and nimble. I know, OP didn't ask for that - but it sounds like the inception phase of a product, and I can't imagine working any other way than "release early, release often". Long-time support viable? Very probable.