Not only do this, but do it way more successfully. I'll never get tired of repeating that among top YC startups, Java as a primary language contributes to roughly 1% of value, while Python + Ruby are almost at 70%.
If by successfully you mean time to market, for sure you are right.
C++ gives more return when you start to save in infra because you have a more efficient language, if coded properly. Same goes for Go vs Python.
The right tool for the right job. I would use (and will, I am on it) Django for a SaaS that I have for the backend. If things start to work relatively well, then, I will keep identifying, if there are, bottlenecks and migrate with a hybrid architecture parts of the workload to C++.
Yet, somehow people do this with python, perl, and ruby. Google hires professional python people too.