Hi Pawel,
I have 8 years of Java/J2EE development experience and i know Retrofit library. Apart from that i am good in Git, IntelliJ and Crypto exchanges.
Recently i completed the top 40 exchange Public Feed integration, the Bitstamp you mentioned that i already done integration. Apart from Btstamp i also completed Binance, Bitfinex, Huobi, Bittrex, and many other Exchange Pubic API/Websocket integration.
I gone through your attached requirement document and it's looking good to me and i would like to discuss further with you. Please feel free to message me.
Thanks,