`initI18n` runs in the client `init()` hook and blocks the first render. For
every non-English user it awaited TWO locale dictionaries back to back — the
active locale AND `en` (the fallback) — so first paint waited on two sequential
round-trips + JSON parses.
Now it awaits only the active locale, then warms `en` in the background
(non-blocking). `t()` only consults `dicts.en` for keys the active locale is
missing, and most call sites already pass an inline English fallback, so the
deferred `en` doesn't change what users see; when it arrives `dicts.en` is
reactive, so any key that fell through re-renders. English users are unchanged
(no second fetch was ever needed).
Net: non-English startup drops from two blocking locale fetches to one, halving
the i18n payload on the critical path (the server already serves these JSONs
brotli/gzip-compressed via the global CompressionLayer, so the wire cost was
already small — this removes the extra round-trip + parse from first paint).
Validated: new unit test (initI18n resolves while the en fetch is still pending,
en is kicked off in the background, and a key missing from the active locale
falls back once en lands) → 47 frontend tests green; npm run check; prod build.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M8Vb9QHmLZnEMzHz7MrFy6
Claude
a8709b447a