Sequential ledger-like entries in NodeJS with Async/ Await - node.js

Question

I'm designing an accounting/ book-keeping application and my table has the following columns -
Transaction ID
Transaction Details
Amount
Closing Balance
All the transactions are fed to NodeJS function one-by-one through a queue
However, while saving each transaction, I have to fetch the previous transaction to get the last closing balance and add current transaction amount to the same to get the new closing balance
But I have to use async/await to fetch previous transaction so the event loop is free for a few milliseconds during which the function receives a new transaction event from the user. This is causing a lot of inconsistencies with the data as sometimes 2 rows with the same closing balance are inserted.
const prevTransaction = await Transaction.findOne({
where: { userId },
order: [['createdAt', 'DESC']]
})
await Transaction.create({
userId,
amount,
closingBalance: prevTransaction ? prevTransaction.closingBalance + amount : amount,
transactionDate
})
Now if the system receives a lot of events in bulk then there could be some inconsistencies in data due to the gap between GET & INSERT query.
In some scenarios, this is the data that's inserted
ID
Amount
ClosingBalance
1
20
20
2
20
40
3
20
40
4
10
50
5
20
60
When ideally it should be -
ID
Amount
ClosingBalance
1
20
20
2
20
40
3
20
60
4
10
70
5
20
90
Any particular way I could tweak the above code to get the sequential effect?
This is the reason I'm using a BullJS queue is so that transactions are processed one-by-one. But this issue still persists because of the 2 await calls.

Answer 1

I have temporarily solved this problem by pausing the job queue if any transaction is being processed and resuming it once the transaction is inserted - link
Would love to hear about any alternate approaches since this approach is relying on a third-party library.