Starting on January 25, the default rate limit will be changed from 100 calls per second to 10 calls per second. This change is being made to allow customers to receive errors as a result of excessive usage so that users can take action to reduce usage before their daily quota is reached. The daily quota remains unchanged. REST API users are encouraged to follow best practices in implementing retry logic and exponential backoff mechanisms to optimize API performance.
Details about usage limits can be found here https://developer-portal.cvent.com/documentation#section/Getting-started/Rate-Limits