You will need to code bitcoin and ethereum online wallet.
Wallet like [url removed, login to view]
- It NEEDS to use bitcoin & ethereum daemon, NO API'S (for example NO block io API etc.)
- It needs to be scalable for 1000s people
- It can't use getBalance method as it's not good scalable, it will scan the entire database.
I suggest you to do accounting using Database and use listsinceblock to track TXs and to update record accordingly. As it will be better for scalability.
- It needs to have function for send & receive BTC/ETH.
- Users can generate new addresses (up to 7 for every BTC/ETH)
- No 3rd party software/services/APIs
- Login/register feature
- Store all data including addresses,private addresses etc in database
- Real time notification if user receive btc/eth - play sound if he receive it and he has wallet open.
- Don't use [url removed, login to view] as it's not scalable good.
- Password reset/forget feature
- It needs to have very good optimalization
- It needs to handle 1000s of people online !! It needs to have good scalability.