How we halved DNS build delay and cut memory use by 85%

Cloudflare describes how its DNS Zone Builder now plans the smallest build it can prove safe, rather than rebuilding whole zones when a setting changes, and merges queued work per zone in one scheduler. Peak memory fell 85% (79 to 12 GiB), and median delay from change to Quicksilver write halved, from about 7.7 to 3.3 seconds. About 93% of builds no longer rebuild the full zone. The figures are Cloudflare's own and not independently verified. The mirror comparison of delay covered one 24-hour period.