Give me an example of how to build an Order Matching Bot in drift

How To Get Balance in a Program Is it possible to get SOL balance and/or SPL token balances for a given account in an Anchor program?

Deriving an associated token account address How can I derive an associated token account address for a given wallet address and token mint?

How can one paginate large number of accounts fetch on solana? Like fetching all candy machines using get .all() api of anchor ? How can one paginate the data or we can't until all accounts data is fetched ?

How do I make a program immutable? Say I have a deployed Solana Program with an upgrade authority. What is the best practice to revoke this authority?

Is there any way to check transaction status of spl transfer using signature hash. like we did on solscan using signature hash to find the transaction status of spl token.