diff --git a/Meta/Lagom/Tools/CodeGenerators/LibLocale/GenerateLocaleData.cpp b/Meta/Lagom/Tools/CodeGenerators/LibLocale/GenerateLocaleData.cpp
index e30d4cba3cd..aa6f39964ec 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibLocale/GenerateLocaleData.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibLocale/GenerateLocaleData.cpp
@@ -199,11 +199,23 @@ struct CLDR {
     Vector<Alias> locale_aliases;
 
     Vector<DeprecatedString> languages;
+    HashMap<StringView, size_t> language_indices;
+
     Vector<DeprecatedString> territories;
+    HashMap<StringView, size_t> territory_indices;
+
     Vector<DeprecatedString> scripts;
+    HashMap<StringView, size_t> script_indices;
+
     Vector<DeprecatedString> variants;
+    HashMap<StringView, size_t> variant_indices;
+
     Vector<DeprecatedString> currencies;
+    HashMap<StringView, size_t> currency_indices;
+
     Vector<DeprecatedString> date_fields;
+    HashMap<StringView, size_t> date_fields_indices;
+
     Vector<Alias> date_field_aliases {
         // ECMA-402 and the CLDR refer to some date fields with different names. Defining these aliases
         // means we can remain agnostic about the naming differences elsewhere.
@@ -332,20 +344,29 @@ static ErrorOr<void> parse_identity(DeprecatedString locale_path, CLDR& cldr, Lo
 
     if (territory_string.has_value()) {
         locale.territory = territory_string.value();
-        if (!cldr.territories.contains_slow(*locale.territory))
+
+        if (!cldr.territory_indices.contains(*locale.territory)) {
+            cldr.territory_indices.set(*locale.territory, 0);
             cldr.territories.append(*locale.territory);
+        }
     }
 
     if (script_string.has_value()) {
-        auto script = script_string.value();
-        if (!cldr.scripts.contains_slow(script))
+        auto const& script = script_string.value();
+
+        if (!cldr.script_indices.contains(script)) {
+            cldr.script_indices.set(script, 0);
             cldr.scripts.append(script);
+        }
     }
 
     if (variant_string.has_value()) {
         locale.variant = variant_string.value();
-        if (!cldr.variants.contains_slow(*locale.variant))
+
+        if (!cldr.variant_indices.contains(*locale.variant)) {
+            cldr.variant_indices.set(*locale.variant, 0);
             cldr.variants.append(*locale.variant);
+        }
     }
 
     return {};
@@ -387,8 +408,10 @@ static ErrorOr<void> preprocess_languages(DeprecatedString locale_path, CLDR& cl
     auto const& languages_object = locale_display_names_object.get_object("languages"sv).value();
 
     languages_object.for_each_member([&](auto const& key, auto const&) {
-        if (!key.contains("-alt-"sv) && !cldr.languages.contains_slow(key))
+        if (!key.contains("-alt-"sv) && !cldr.language_indices.contains(key)) {
+            cldr.language_indices.set(key, 0);
             cldr.languages.append(key);
+        }
     });
 
     return {};
@@ -406,8 +429,10 @@ static ErrorOr<void> preprocess_currencies(DeprecatedString numbers_path, CLDR&
     auto const& currencies_object = locale_numbers_object.get_object("currencies"sv).value();
 
     currencies_object.for_each_member([&](auto const& key, JsonValue const&) {
-        if (!cldr.currencies.contains_slow(key))
+        if (!cldr.currency_indices.contains(key)) {
+            cldr.currency_indices.set(key, 0);
             cldr.currencies.append(key);
+        }
     });
 
     return {};
@@ -435,8 +460,10 @@ static ErrorOr<void> preprocess_date_fields(DeprecatedString dates_path, CLDR& c
         if (!is_sanctioned_date_field(key))
             return;
 
-        if (!cldr.date_fields.contains_slow(key))
+        if (!cldr.date_fields_indices.contains(key)) {
+            cldr.date_fields_indices.set(key, 0);
             cldr.date_fields.append(key);
+        }
     });
 
     return {};
@@ -532,7 +559,7 @@ static ErrorOr<void> parse_locale_languages(DeprecatedString locale_path, CLDR&
         if (key.contains("-alt-"sv))
             return;
 
-        auto index = cldr.languages.find_first_index(key).value();
+        auto index = cldr.language_indices.get(key).value();
         languages[index] = cldr.unique_strings.ensure(value.as_string());
     });
 
@@ -563,7 +590,7 @@ static ErrorOr<void> parse_locale_territories(DeprecatedString locale_path, CLDR
     auto const& territories_object = locale_display_names_object.get_object("territories"sv).value();
 
     territories_object.for_each_member([&](auto const& key, JsonValue const& value) {
-        if (auto index = cldr.territories.find_first_index(key); index.has_value())
+        if (auto index = cldr.territory_indices.get(key); index.has_value())
             territories[*index] = cldr.unique_strings.ensure(value.as_string());
     });
 
@@ -594,7 +621,7 @@ static ErrorOr<void> parse_locale_scripts(DeprecatedString locale_path, CLDR& cl
     auto const& scripts_object = locale_display_names_object.get_object("scripts"sv).value();
 
     scripts_object.for_each_member([&](auto const& key, JsonValue const& value) {
-        if (auto index = cldr.scripts.find_first_index(key); index.has_value())
+        if (auto index = cldr.script_indices.get(key); index.has_value())
             scripts[*index] = cldr.unique_strings.ensure(value.as_string());
     });
 
@@ -713,7 +740,7 @@ static ErrorOr<void> parse_locale_currencies(DeprecatedString numbers_path, CLDR
         auto narrow_name = value.as_object().get_deprecated_string("symbol-alt-narrow"sv);
         auto numeric_name = value.as_object().get_deprecated_string("displayName-count-other"sv);
 
-        auto index = cldr.currencies.find_first_index(key).value();
+        auto index = cldr.currency_indices.get(key).value();
         long_currencies[index] = cldr.unique_strings.ensure(move(long_name));
         short_currencies[index] = cldr.unique_strings.ensure(move(short_name));
         narrow_currencies[index] = narrow_name.has_value() ? cldr.unique_strings.ensure(narrow_name.release_value()) : 0;
@@ -790,7 +817,7 @@ static ErrorOr<void> parse_locale_date_fields(DeprecatedString dates_path, CLDR&
         auto const& short_name = fields_object.get_object(DeprecatedString::formatted("{}-short", key))->get_deprecated_string("displayName"sv).value();
         auto const& narrow_name = fields_object.get_object(DeprecatedString::formatted("{}-narrow", key))->get_deprecated_string("displayName"sv).value();
 
-        auto index = cldr.date_fields.find_first_index(key).value();
+        auto index = cldr.date_fields_indices.get(key).value();
         long_date_fields[index] = cldr.unique_strings.ensure(long_name);
         short_date_fields[index] = cldr.unique_strings.ensure(short_name);
         narrow_date_fields[index] = cldr.unique_strings.ensure(narrow_name);
@@ -1030,11 +1057,19 @@ static ErrorOr<void> parse_all_locales(DeprecatedString bcp47_path, DeprecatedSt
         return IterationDecision::Continue;
     }));
 
-    quick_sort(cldr.languages);
-    quick_sort(cldr.territories);
-    quick_sort(cldr.scripts);
-    quick_sort(cldr.currencies);
-    quick_sort(cldr.date_fields);
+    auto update_indices = [](auto& keys, auto& indices) {
+        quick_sort(keys);
+
+        for (size_t i = 0; i < keys.size(); ++i)
+            indices.set(keys[i], i);
+    };
+
+    update_indices(cldr.languages, cldr.language_indices);
+    update_indices(cldr.territories, cldr.territory_indices);
+    update_indices(cldr.scripts, cldr.script_indices);
+    update_indices(cldr.variants, cldr.variant_indices);
+    update_indices(cldr.currencies, cldr.currency_indices);
+    update_indices(cldr.date_fields, cldr.date_fields_indices);
 
     TRY(Core::Directory::for_each_entry(TRY(String::formatted("{}/bcp47", bcp47_path)), Core::DirIterator::SkipParentAndBaseDir, [&](auto& entry, auto& directory) -> ErrorOr<IterationDecision> {
         auto bcp47_path = LexicalPath::join(directory.path().string(), entry.name).string();