...
https://docs.microsoft.com/en-us/graph/json-batching
Given we have 1,000 users, we can fetch them in 3 requests, resulting in about ~1.5s * 3 = ~4.5s. Given we have 10,000 users, we should be able to fetch all users' statuses in 25 requests, resulting in about ~1.5s * 25 = ~37.5s if done synchronously. Splitting up the work into goroutines should work nicely since each request is completely independent from the others.
...
Test the roundtrip of a batch request with realistic user data
Build the auth flow to include admin consent: https://docs.microsoft.com/en-us/graph/auth-v2-service#3-get-administrator-consent
Better error handling for requests, including batch requests. This includes notifying admins of failures.
Research and test rate limiting of Microsoft’s APIs
Test that the order of availabilities in each batch response is valid.