For example : WorkingTask App. I use Redux - React

**Structure** 

JobOrders (collections) / eachJob (docu)

```
- the app is allow only insert new JOB.
- the whole day has 500-1000 Jobs.
- the all jobs must be used to recompute the report realtime.  
- clear data once every midnight.

```

I know how to fetch and listen-realtime callback for the whole.
but the problem is the callback function must recompute the whole documents (maybe 300-1000 Jobs every-time when a new JOB arrived.)

This is I want: 

```
- every new JOB arrived only new data in callback then I can recompute in REDUX.  

- and prevent for some data is delay due to internet network connection.

```

I come across with : to listen limit to 1 and sortBy timestamp 'desc'.

**But the problem is if some JOB are delay due to network connection, it will not call in callback.**