Hello,
I'm in electronics design and automation for over 10 years, dealing with any kind of circuits and technologies. I have developed several projects using Arduino.
In your case I would implement a web server into Arduino in order to handle GET, HEAD, POST, PUT, DELETE, PATCH methods, and a JSON/RESTful interface. In this case you will connect the WiFi to the Arduino and control it's ports/interfaces either for read or write.
In my opinion, if you intend to have build a product for mass production, I would recommend using a "barebone" microcontroller in order to avoid the overhead caused by the Arduino SDK, get the most out of the chip and also chose the best chip for your application, based on number of I/O pins, peripherals and speed, and at the end save some money leaving apart Arduinos' marketing.
I can complete your project in around 2 weeks, but I can give you a realistic delivery time once you give me more details on exactly what functionalists you need implemented in.