Format monetary values, numbers, and dates using the browser's built-in Intl.NumberFormat and Intl.DateTimeFormat APIs instead of manual string manipulation.
Select the correct grammatical plural category for every language using Intl.PluralRules or an ICU-aware i18n library instead of simple singular/plural branching.
Default to abstract, culture-neutral icons and illustrations, and supply locale-specific image variants only when visual content carries meaning that differs across regions.