Real-Time Multilingual Text Translator

I need a developer to build a text-only translation solution that can work in both real-time streaming and traditional batch mode. The first release must reliably cover three language pairs—English↔Spanish, French↔German, and Chinese↔English—switching direction automatically when required.

You’re free to choose the stack that best balances speed and accuracy; Python with FastAPI, Node.js with Express, or a lightweight C++ service are all acceptable as long as the final service exposes clear REST or WebSocket endpoints for live translation and a straightforward file-upload route for batch jobs. Leveraging services such as Google Cloud Translation, AWS Translate, or open-source transformer models is fine, provided latency in the real-time path remains under a second for short sentences and overall BLEU scores stay competitive.

Deliverables will be:
• A working service (containerised or self-hosted) with real-time and batch endpoints
• Brief setup documentation plus example curl or websocket calls
• A concise test report showing latency and accuracy for the three language pairs

If you have prior experience optimising multilingual NLP pipelines, please mention it along with any live demos or repos I can inspect.