Improving Performance with Background Data Prefetching
Article Summary
Instagram serves 800 million monthly users, 80% outside the US. How do you make the app feel instant for everyone, regardless of network quality?
Instagram Engineering shares how they built a centralized background data prefetching system that loads content before users need it. The framework now powers Explore, Stories, and the main feed.
Key Takeaways
- Built centralized framework flexible enough to adapt across different content types
- Leveraged existing offline mode cache infrastructure to store prefetched content
- Decouples app usability from network availability while minimizing cellular data usage
- Separate endpoint returns newest 20 feed items not in view state
- Prioritizes content based on user behavior patterns and available resources
Background prefetching dramatically improved perceived app speed across Instagram's core features without negatively impacting battery life or data usage.
About This Article
Instagram Engineering needed to figure out when to prefetch content in the background, which framework would work best, and how to keep things efficient as they scaled across different use cases and content types.
The team built a centralized framework with a dedicated endpoint for background prefetching. It returns the newest 20 feed items that aren't currently visible and plugs into the existing offline mode cache.
The system rolled out to Explore, Stories, and the main feed. It made the app feel noticeably faster without draining battery life or using more cellular data, even at Instagram's scale of 800 million monthly users.