Chess coding languages

I invented a game of double Chess called Synergy Chess, which is free to play online. People can play against humans or bot. I am not a coder. I hired someone to write the program. The game is written in Node.js, React.js, Xitrium, Scala and Java. This makes it very difficult to find people that can work on it. After doing some research on Wikipedia I discovered that chess dot com was launched 15 years ago. This is written in Java, JavaScript and PHP. They have over 100,000,000 registered online players. If they can use simpler languages, then why can’t I? I am trying to find out if chess dot com is still written this way. If it is, then there is no reason why Synergy Chess can’t be simplified, even if I have to start form scratch and have it rewritten. l am looking for some solid advice here please.