# Performance Issue: Slow Event Fetching from Outlook Integration

**URL:** <https://forums.nylas.com/t/performance-issue-slow-event-fetching-from-outlook-integration/839>\
**Category:** Question and Answers\
**Tags:** calendar-api, events\
**Created:** [August 5, 2025, 2:15pm UTC](https://forums.nylas.com/t/performance-issue-slow-event-fetching-from-outlook-integration/839 "2025-08-05T14:15:33Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Niroz](https://avatars.discourse-cdn.com/v4/letter/n/278dde/32.png) [@Niroz](https://forums.nylas.com/u/Niroz)\
**Post date:** [August 5, 2025, 2:15pm UTC](https://forums.nylas.com/t/performance-issue-slow-event-fetching-from-outlook-integration/839/1 "2025-08-05T14:15:33Z")

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I’m integrating our application with Nylas to fetch calendar events from both Google and Outlook, using the following endpoint :  
`https://api.eu.nylas.com/v3/grants/$grantId/events`

I’ve observed a significant performance difference between the two providers:

- Fetching events from **Outlook** frequently takes **20 seconds or longer** , even when requesting events over just a one-month period and when the calendar contains very few or no events.

- Fetching events from **Google Calendar** is consistently fast and responsive under identical conditions.

Could you help me understand the reason behind these slow responses specifically from Outlook, or suggest improvements to enhance performance?  
Thanks a lot

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**Author:** ![ram](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.nylas.com/ram/32/3_2.png) [@ram](https://forums.nylas.com/u/ram)\
**Post date:** [August 7, 2025, 3:17pm UTC](https://forums.nylas.com/t/performance-issue-slow-event-fetching-from-outlook-integration/839/2 "2025-08-07T15:17:25Z")

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Hi @Niroz thanks for posting.

So from your experience, fetch Outlook events takes significantly longer compared to Google Calendar events. For the Outlook request - does it make a different if fetching fewer days?

Also, could you share the entire call to the endpoint, as a code sample?

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<div class="post-metadata">

**Author:** ![ram](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.nylas.com/ram/32/3_2.png) [@ram](https://forums.nylas.com/u/ram)\
**Post date:** [August 7, 2025, 5:02pm UTC](https://forums.nylas.com/t/performance-issue-slow-event-fetching-from-outlook-integration/839/3 "2025-08-07T17:02:00Z")

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Also, it will be useful to [try out field selection to reduce the response data size](https://developer.nylas.com/docs/dev-guide/best-practices/rate-limits/#reduce-response-size-with-field-selection).