P99 0 ms autocomplete for 240 million domain names

P99 0 ms* autocomplete for 240M domain names

Wirewiki founder explains how to achieve p99 0 ms autocomplete for 240M domains. The trick: prefetch suggestions on keyDown, render on keyUp, hiding API latency between keystrokes. API uses an in-memory trie for popular domains and an SSD-backed block index for the tail, both effectively O(1). Load tests show API p99 at 15 ms, but cross-continent network latency exceeds the budget. The post doesn't disclose server specs or CDN setup.