# Scaling integrations with bulk, async and big objects

*Integration Architect Study Guide · Build Solution · Last updated October 16, 2026 · https://www.certifyforce.com/study-guide/integration-architect/build-solution/scaling-integrations-with-bulk-async-and-big-objects*

What makes an integration scale: Bulk API 2.0 versus bulkified REST by volume and latency, cutting API calls with composite requests, automatic PK chunking for big extracts, Batch Apex concurrency and callout sizing, bulkified triggers and the shared async limit, 70% headroom with production-scale load tests, big objects for long-term logs and event fan-out for new consumers.

- Certification: Salesforce Integration Architect
- Exam section: Build Solution
- Study guide: https://www.certifyforce.com/study-guide/integration-architect

**Official exam objective:**

> Given a use case, describe what should be considered when building a scalable solution.

## What the exam expects

- Choose Bulk API 2.0, bulkified synchronous REST or virtualization from volume, latency and where the data must live.
- Reduce API consumption with composite requests and bulk jobs, and extract very large tables without timeouts.
- Size Batch Apex for concurrency and callouts, bulkify triggers on loaded objects, and avoid flooding the shared async limit.
- Set scalability standards: headroom below governor limits, production-scale load tests, big objects for multi-year logs, events for growing consumer lists.

Key terms: **bulkified** (one operation handles a collection, not one record); **PK chunking** (splitting a bulk query by record ID ranges); **flex queue** (where submitted batch jobs wait in Holding status); **headroom** (the share of a limit left unused for spikes); **big object** (a horizontally scalable store for hundreds of millions of records).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Bulk API 2.0 threshold | More than 2,000 records; fewer use bulkified REST or SOAP | [Bulk API intro](https://developer.salesforce.com/docs/platform/api-asynch/guide/asynch-api-intro.html) |
| Composite and Collections | Whole request counts as one API call | [Composite](https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/resources_composite_composite.htm), [sObject Collections](https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/resources_composite_sobjects_collections.htm) |
| API allocation scope | Org-wide aggregate per 24 hours, not per user | [API Request Limits](https://developer.salesforce.com/docs/platform/salesforce-app-limits-cheatsheet/guide/salesforce-app-limits-platform-api.html) |
| PK chunking | Automatic in Bulk API 2.0 queries; manual header in original Bulk API | [Bulk API 2.0 vs Bulk API](https://developer.salesforce.com/docs/atlas.en-us.api_asynch.meta/api_asynch/bulk_common_diff_two_versions.htm) |
| Batch concurrency | 5 queued or active; 100 Holding in the flex queue | [Use Batch Apex](https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_batch_interface.htm) |
| Batch callouts | `Database.AllowsCallouts`; up to 100 per start, execute or finish | [Use Batch Apex](https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_batch_interface.htm) |
| Daily async executions | 250,000 or licenses x 200, whichever is greater; org-wide | [Execution Governors and Limits](https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_gov_limits.htm) |
| Headroom target | 70% of governor limits under normal load | [Reliability (Well-Architected)](https://architect.salesforce.com/docs/architect/well-architected/guide/reliability.html) |
| Big object scale | Consistent performance up to billions of records | [Big Objects](https://developer.salesforce.com/docs/atlas.en-us.bigobjects.meta/bigobjects/big_object.htm) |

## Check yourself

- Why does a Bulk API 2.0 extract not need the PK chunking header?
- When should a load use bulkified REST instead of Bulk API 2.0?
- How many batch jobs can be queued or active at once in an org?
- Why load test in a Full Copy sandbox instead of a small sample?

## Sources

- [Introduction to Bulk API 2.0 and Bulk API](https://developer.salesforce.com/docs/platform/api-asynch/guide/asynch-api-intro.html)
- [What's the Difference Between Bulk API 2.0 and Bulk API?](https://developer.salesforce.com/docs/atlas.en-us.api_asynch.meta/api_asynch/bulk_common_diff_two_versions.htm)
- [PK Chunking](https://developer.salesforce.com/docs/atlas.en-us.api_asynch.meta/api_asynch/async_api_headers_enable_pk_chunking.htm)
- [Composite](https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/resources_composite_composite.htm)
- [sObject Collections](https://developer.salesforce.com/docs/atlas.en-us.api_rest.meta/api_rest/resources_composite_sobjects_collections.htm)
- [API Request Limits and Allocations](https://developer.salesforce.com/docs/platform/salesforce-app-limits-cheatsheet/guide/salesforce-app-limits-platform-api.html)
- [Use Batch Apex](https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_batch_interface.htm)
- [Execution Governors and Limits](https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_gov_limits.htm)
- [Reliability (Well-Architected)](https://architect.salesforce.com/docs/architect/well-architected/guide/reliability.html)
- [Big Objects](https://developer.salesforce.com/docs/atlas.en-us.bigobjects.meta/bigobjects/big_object.htm)
- [Big Objects Best Practices](https://developer.salesforce.com/docs/atlas.en-us.bigobjects.meta/bigobjects/big_object_considerations.htm)
- [Data Integration Decision Guide](https://architect.salesforce.com/docs/architect/decision-guides/guide/data-integration.html)
- [Event-Driven Architecture Decision Guide](https://architect.salesforce.com/docs/architect/decision-guides/guide/event-driven.html)
- [Integration Patterns](https://architect.salesforce.com/docs/architect/fundamentals/guide/integration-patterns.html)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 11 linked practice questions, and unlimited timed mock exams are included with the Integration Architect pack (USD $19): https://www.certifyforce.com/practice-exams