Need a Node JS developer to create a server

I have a multiple player game for which I need to create Unity Engine Any Dedicated Server on Node.js with Socket.IO (Connect between Unity3d and Node.js). Database will be Mongo DB.

Please mentioned the answers to below questions in your bid.

1. Will it be a micro services based architecture?
2. If yes how does the intercommunion will happen between services?
3. Are the game servers stateful or stateless?
4. If stateless where will you be maintaining state of game?
5. In case of game servers crash, can they resume the game from where it stopped?
6. Why do we believe that servers can scale to millions of concurrent users?
7. All the DB operations are asynchronous in nature?
8. How are we taking care of thread management?

Only bid if you can answer the above questions else don't waste my time.