Batch APIs in Node.js: Where Most Systems Fail

Batch APIs look simple at first.

Send many records -> process them -> done.

But reality is different 😄

If one record has bad data.
And suddenly because of that:

• The entire batch failed.
• 999 good records get punished.
• The client has no idea what actually going wrong.

Another common problem:

• The API always returns 200 OK.
• But half the records quietly failed.
• No clear success or failure details.

And retries?
Usually it’s just:

• Retry the whole batch.

Now the system:

• Reprocesses records that already succeeded.
• Creates duplicate data.
• Wastes time and resources.

A good batch API should:

• Handle each record separately.
• Clearly show what worked and what didn’t.
• Retry only the failed records.
• Do its job without surprises.

Batch processing isn’t about handling a lot of data.
It’s about handling bad data without breaking the rest.

If you worked with Node.js batch jobs, queues, or async workers.
You have definitely seen this 😅 and you can relate.