The maximum number of API calls an org can make in a rolling 24 hour period / External system makes 100000 calls a day when the org limit is 50000 / ETL tool runs a mid day sync and consumes remaining API calls blocking other integrations / Error TotalRequests Limit exceeded REQUEST_LIMIT_EXCEEDED / Monitor usage with Limits API and use retry logic
API call limits
The limit of how many inbound API requests lasting 20 seconds or longer can run simultaneously / Complex dataload process takes 30 seconds due to backend automation / Multiple data loader instances exceed limit causing subsequent calls to fail / Error ConcurrentRequest Limits exceeded Unable to process requests / Prod and Sandboxes 25 seconds Dev orgs 5 seconds
Concurrent long running calls
Maximum heap memory a single Apex transaction can consume 6MB synchronous 12MB asynchronous / Integration queries objects into a list without filters or batching / Synchronous Apex REST service tries to hold inbound data in memory causing overflow / Error System.LimitException Apex heap size too large / Avoid loading entire datasets use SOQL for loops serialize large payloads
Heap size limits
Total execution time allowed for Apex 10 seconds synchronous 60 seconds asynchronous / Trigger performs nested loops queries and DML on large volumes / Bulk API loads trigger inefficient automation exceeding CPU limit / Error Apex CPU time limit exceeded / Bulkify code move heavy logic async
CPU time limits
Salesforce locks records during DML and integrations may be blocked / External system and batch job update the same Account / Scheduled job locks thousands of records and API updates fail / Error UNABLE_TO_LOCK_ROW / Use deterministic locking process parent before child handle errors
Row locking behavior
Limit on number of event messages or CDC events that can be delivered / Integration subscribes to Account CDC and org exceeds event allocation / Surge in data changes causes delivery quota exceeded / Error Event delivery limit exceeded / Monitor event metrics batch changes
Event delivery limits
Platform Events have hourly limits PushTopic events have daily limits and subscriber count multiplies consumption / High subscriber count rapidly consumes PushTopic allocations / Subscriber growth causes unexpected limit consumption / Monitor subscriber counts consider Platform Events for high fanout
Streaming and Platform Event limits
Salesforce automation runs in a structured sequence triggers validation rules flows etc / API update triggers process builder and Apex trigger / Poor design causes infinite loops CPU limit errors and DML failures / Error Apex CPU time limit exceeded Maximum trigger depth exceeded / Understand order of execution and prevent recursion
Order of execution impacts
A maximum of 100 HTTP requests or web service calls are allowed in a single Apex transaction.
Total Callouts
The total cumulative timeout across all callouts in a transaction is 120 seconds.
Cumulative Timeout
The default timeout for a single callout is 10 seconds; you can set a custom timeout up to the cumulative limit
Individual Callout Timeout
Maximum response size is 6 MB for synchronous callouts and 12 MB for asynchronous callouts
Response Size
You cannot perform DML operations (insert, update, delete) between multiple callouts in the same synchronous transaction context
DML Restrictions
