Theme 1 – Perceived latency matters more than raw timing, and using keyup hurts UX
- “When it comes to UX, perceived latency is king.” – dbalatero
- “The perceived latency starts from keydown, not keyup. Redefining latency to start at keyup reduces measured latency, not perceived latency, and delaying the visual display to keyup makes perceived latency strictly worse.” – wky
- “Using keyup makes no sense and is inconsistent with user expectations.” – chrismorgan
Theme 2 – Speculative pre‑fetch / prediction techniques can shave latency
- “They already did a search based on the previous characters that returned results for all possible next characters. So by the time you type a second character it just checks results locally from the search that had likely already been returned from when you had typed the previous character.” – weird‑eye‑issue
- “I think you could get a lot closer by framing this as an optimization problem… add a residual prediction which aims to cover as much of the remaining domain name tree as possible weighted by popularity.” – ViscountPenguin
- “If you’d like to reduce the network latency further you can store each trie node as a file… dump the few hundred million files onto R2… Now the traversal can be done completely via CDN lookups!” – kevmo314
Theme 3 – Real‑world constraints limit the usefulness of ultra‑low latency tricks
- “KeyDown events don’t work great for mobile.” – cortesoft
- “What happens when someone pastes a domain or uses IME or voice input?” – ChannelFence
- “Once you factor in monitor refresh rates then you can get to levels of optimization where it simply doesn't matter because you are constrained by waiting for the refresh rate anyways.” – weird‑eye‑issue
- “This autocomplete suggests domains that don't exist… makes it less useful.” – skybrian