Plus, where's the coverage about Japanese companies in China?
The usual term for software that connects frontend and backend is "middleware". It's definitely not something Alibaba invented, although they might have popularized the concept in China.
For translations of technical terms, I recommend trying to search for your proposed translation plus context-relevant keywords and see whether there are usage examples. Doing that for "frontend backend middle platform" leads me to this StackOverflow question about the difference between the three: https://stackoverflow.com/questions/636689/difference-between-frontend-backend-and-middleware-in-web-development
The usual term for software that connects frontend and backend is "middleware". It's definitely not something Alibaba invented, although they might have popularized the concept in China.
For translations of technical terms, I recommend trying to search for your proposed translation plus context-relevant keywords and see whether there are usage examples. Doing that for "frontend backend middle platform" leads me to this StackOverflow question about the difference between the three: https://stackoverflow.com/questions/636689/difference-between-frontend-backend-and-middleware-in-web-development