Instant Transactions: Private vs Public Blockchain

Question

I have been developing a smart contract with solidity. My question is related to the deployment of smart contracts. I have studied and followed answers in the following links:

Main Network vs Private Network: pro and cons

Private BlockChain - Cons?

Private blockchain for production?

But I am still confused about the time it will take to reflect changes real-time in common use cases. For example, in the case of transferring Ether from one wallet to another, it may take some time in minutes or hours depending on circumstances, like from one exchange to another, etc.

So if I create a contract for exchanging assets or tokens from one account to another, will it be reflected instantaneously on both accounts if the contract is deployed on the mainnet or will it take time for that to happen?

If I want transactions to be instant, should I use a private blockchain using Geth or the public mainnet blockchain?

Answer 1

Main Network vs Private Network is a trade off based on numerous factors of your dApp.

But specific to your need where you want transactions to be instant (or more precisely close to instant ) you could offer a high transaction fee as reward and it should be much much faster compared to other transactions and probability of getting your transaction added to block by a miner would be quite high.