You are using or planning to use ToDo Odata API to implement your integration.
SAP SuccessFactors HCM Suite OData API
Reproducing the Issue
There are two API entry points whereby you can use to fetch a list of tasks (to-do items) assigned to a user for integration, ToDo and TodoEntryV2.
It is highly encouraged to use TodoEntryV2 entity instead of ToDo as there is a limitation with this legacy ToDo entity.
ToDo entity only allows you to query the logged-in user's to-do items. User authentication is required for every request. This means a new session is created on the server for each API call, and each session will trigger an insert operation to the database for authentication audit. A high volume of simultaneous ToDo requests occupies a great amount of resource and could drastically slow down system performance.
TodoEntryV2, on the other hand, allows you to query the to-do items of multiple users in one request, hence, only one user authentication is needed and one login record will be logged.
Query the to-do items of multiple users in one request using TodoEntryV2 entity instead of ToDo to avoid slow system performance caused by associated high load of authentication auditing.
ToDo OData API, TodoEntryV2, authentication audit , KBA , LOD-SF-INT-ODATA , OData API Framework , LOD-SF-PLT-LIS , Log In Issues with Infra Issues , Product Enhancement