OSS + ELC EU 2026

Kraken is Uber's open-source P2P container registry. It serves 23 petabytes of data daily with 99.9% reliability. However, during recovery from a complete regional failure, Kraken was pushed over its historical peak load by 10 times. It had to distribute over 100,000 container images every minute. The registry that "just worked" became the bottleneck blocking disaster recovery.

Adding capacity proved insufficient. So, the team reworked the caches and tuned download parallelism. But closing such a large performance gap required architectural changes. If downloads are too slow, move the data closer to the client. If you cannot serve everything at once, tier images by criticality. These optimizations eventually broke Uber’s deployment throughput record.

This talk presents a case study of evolving Kraken to deliver 10x performance under extreme load - the architectural changes, necessary trade-offs, and hard-won lessons. All optimizations are open-sourced in Kraken.