CCA Prep
CCAR-FUA

Lesson 4.5Lesson 23 of 30

Batch processing strategies

Design efficient batch processing strategies

Batch processing strategiesIs anyone waiting on the result?yes, it blocks a person ora mergeSynchronous APIno, overnight or weeklyworkMessage Batches API50% cheaper, up to 24 hneeds several tool-callingturnsSync loop, or data inthe promptno tool loop inside a batchrequestJoin by custom_id; resubmit only failed items, fixed first

Key points

  1. 1The Message Batches API costs 50% less than synchronous calls, but a batch may take up to 24 hours and has no latency guarantee. Most batches finish sooner; never design around "usually".
  2. 2Batch fits work nobody waits on: overnight reports, weekly audits, nightly test generation. A pre-merge check a developer is blocked on stays on the synchronous API.
  3. 3One batch request is one Messages call: no multi-turn tool calling inside it. If Claude answers with tool_use, nobody runs the tool. Put the needed data in the prompt, or keep the tool loop synchronous.
  4. 4Results can come back in any order: join them by custom_id (a stable document id), never by position. Resubmit only the failed custom_ids, fixed first (chunk documents that were too long); re-send expired ones as is.
  5. 5Derive submission frequency from the SLA: 30 h SLA − 24 h worst-case batch − 2 h post-processing = submit every 4 h. Before a large batch, refine the prompt on a representative sample to maximise first-pass success.
What the exam guide checks here

Objective wording from the exam guide (English).

  • 4.5.K1Message Batches API: 50% cheaper, up to 24 h, no latency SLA
  • 4.5.K2Batch for latency-tolerant work, not blocking pre-merge checks
  • 4.5.K3Batch does not support multi-turn tool calling inside one request
  • 4.5.K4custom_id correlates requests and responses
  • 4.5.S1Synchronous API for blocking checks, batch for overnight/weekly
  • 4.5.S2Compute submission frequency from SLA (4 h windows for 30 h SLA with 24 h batch)
  • 4.5.S3Resubmit only failed items by custom_id, with fixes (chunk oversized documents)
  • 4.5.S4Refine prompts on a sample before large batches

Lock it in

Answer scenario questions on this topic. Every option comes with an explanation.

Practise 4.5 · 21 questions