What is the technology stack behind kmikeym.com?

Hi guys thank you in advance for your time and attention !

So to explain, I am looking forward to build a similar platform as kmikeym.com. Which is a fully functional stock market allowing anyone to become stakeholder in the future of Kenneth mike merill.

If anybody could help me figure out about the network protocols - Does UDP and protocols built on top of UDP to anything TCP are necessary?

Regarding the programming language - I thought using C++, java, for High performance.

About the distributed architecture - I will first be trading my myself and then maybe couple of others people therefore do I really need to think about scalability from the get go and therefore break the system into smaller components. I

Last but not least is the threading model - what do you recommend so I can have the best latency? I heard about LMAX disruptor: Disruptor by LMAX-Exchange

Is there a simpler way of building a fully functional stock market other than what is shown above?

Thanks in advance for anyone stopping by and taking their time to answer !