Engineering
Notes from the network
Capacity planning, routing incidents and the numbers behind them. We publish the awkward ones too.
Serving a 62 GB patch to four million clients
What actually happens to a shield tier when a publisher presses the button, and why origin egress stayed at 340 Mbps.
Why we slice objects at 8 MB and not 2 MB
A tour through three years of slice-size experiments, including the one that halved our NVMe write amplification.
A route leak in São Paulo, and 41 minutes of bad decisions
A transit provider re-announced our prefixes. Here is the timeline, the missing automation, and what we changed.
HTTP/3 is finally boring, and that is the point
38% of our traffic is QUIC. Here is what changed in the congestion control story once we stopped hand-tuning it.
Measuring anycast catchment without synthetic probes
Using real client RTT samples to work out which PoP a network lands on, and what to do when the answer is 'the wrong one'.
Cold storage for warm objects: the shield tier rewrite
We replaced a naive LRU with a cost-aware admission policy and cut origin fetches by 61%.