In Just-in-time funding flow, the balance remains 0 on the actual wallet. The funds are moved to the wallet from the pool account at the time of transaction and moved out for the spent. The characteristics of JIT are:

Certain capping shall be applicable on such wallets on how much the wallet can utilize from the pool account. Example: If the jitSpendCap value for the JIT-enabled wallet is 5000, then it acts as the value till the pool account balance can be used.
If any transaction of 2000 takes place, then the updated jitSpendCap value will be 3000.
jitSpendCap can be increased only by the client by calling the update API request.
By default, for all the JIT-enabled wallets, the jitSpendCap value will be 0.

Creating a JIT Spend Cap involves the following API flow: