Rate limit
Galileo does not specify a default limit on the number of API calls that a program can make; however, it is still possible to overwhelm the system with an excessive number of calls during a given period.
You will need to work with Galileo to calculate a safe upper limit for your program. The factors to take into consideration will vary per program and can include things such as core configuration and transactions per account.
Failure to conform to this upper limit can result in system failure, with high numbers of request failures and other unexpected negative results.
Payload limit
For many endpoints the payload for an endpoint request cannot exceed 16 MB. Some endpoints can handle larger payloads; however, overlarge payloads can overwhelm the system. Check with Galileo to verify payload limits for individual endpoints.