I am attempting to construct a cell software program Pockets made in Flutter with a Bitcoin Core Full node that communicates with a Node.js backend.

The issue I can not discover the reply to is: how can pockets softwares sustain all of the incoming transactions from doubtlessly 1000’s of addresses?

I would not actually prefer to depend on any third get together APIs like blockchain.com however within the different hand Bitcoin Core and bitcoin-cli do not enable me to examine transactions ranging from an addresses aside from those from manually imported wallets (which might be clearly impractical from a software program that’s anticipated to work quick, with a number of HD wallets and largely of all, the place I haven’t got to retailer the non-public key aside from the person machine.).

So, how do wallets work on this regard? Do they depend on a 3rd get together and in that case, how are these events in a position to work in addition to (for instance) blockchain.com? What am I lacking?

If the answer is to import into BC all of the wallets created through Dart, is there a approach to handle 1000’s of customers in a number of Bitcoin Core nodes making certain 100% safety and pace?

Thanks to everybody that gives as many particulars as potential.