Graph find meeting times API Performance Testing & Mitigation Strategies

Problem: Many attendees & Heavy schedule data → 502 Bad Gateway

Solution: Batch attendees + chunk date ranges

Setup

Microsoft Graph supports two access scenarios, delegated access and app-only access. In delegated access, the app calls Microsoft Graph on behalf of a signed-in user. In application-only access, the app calls Microsoft Graph with its own identity, without a signed-in user.

In the scenario of manipulating other users' schedules, you must use application-only access. In delegated access, you can only manipulate your schedule.

This demo script uses application-only access for creating events and cleaning up events. Delegated access is used for find_meeting_times.

1. Register Azure AD Application

1. Go to Azure Portal → Entra ID (Azure Active Directory) → App registrations
2. New registration:
   • Name: FindMeetingTimes POC
   • Supported account types: Single tenant or Multitenant
3. Copy Application (client) ID and Directory (tenant) ID

2. Add API Permissions

1. API permissions → Add permission → Microsoft Graph → Delegated
2. Add permissions (per MS documentation):
   • Calendars.Read.Shared - Required for findMeetingTimes (docs)
   • Calendars.ReadWrite - Required for test data functions (create/delete events)
   • User.Read - Basic user profile
3. User consent via browser: With interactive browser auth, users can consent to these permissions themselves during sign-in.
4. API permissions → Add permission → Microsoft Graph → Application
5. Add permissions and consent by administrator.
6. Manage > Authentication > Settings > Allow public client flows > Enabled

3. Update Code with Credentials

Rename .env.template to .env, and replace placeholders:

AZURE_TENANT_ID=your-tenant-id-here
AZURE_CLIENT_ID=your-client-id-here
AZURE_CLIENT_SECRET=your-client-secret-here
TEST_ATTENDEES="user1@contoso.com, user2@contoso.com, user3@contoso.com"

4. Install Dependencies

uv sync

Usage

1. Schedule data creation for testing: create_events.py
2. Find meeting times API calls with mitigation strategies: find_meetings.py
3. Purge test data: cleanup_events.py

Response sample

{
  "status": 200,
  "data": {
    "meetingTimeSuggestions": [
      {
        "confidence": 87.25,
        "organizerAvailability": "busy",
        "meetingTimeSlot": {
          "start": {
            "dateTime": "2026-01-29T00:30:00.0000000",
            "timeZone": "UTC"
          },
          "end": {
            "dateTime": "2026-01-29T00:40:00.0000000",
            "timeZone": "UTC"
          }
        }
      }
    ],
    "emptySuggestionsReason": ""
  }
}

References

• user: findMeetingTimes API
• Microsoft Graph Python SDK
• Azure Identity