Refactor QuestionsFollowingFeed to optimize query for retrieving foll…

…owed questions

app/Queries/Feeds/QuestionsFollowingFeed.php

@@ -7,6 +7,7 @@
 use App\Models\Question;
 use App\Models\User;
 use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Query\Builder as QueryBuilder;
 use Illuminate\Support\Facades\DB;
 
 final readonly class QuestionsFollowingFeed
@@ -27,7 +28,12 @@ public function builder(): Builder
     {
         $followQueryClosure = function (Builder $query): void {
             $query->where('to_id', $this->user->id)
-                ->orWhereIn('to_id', DB::table('followers')->select('user_id')->where('follower_id', $this->user->id));
+                ->orWhereExists(function (Builder|QueryBuilder $query): void {
+                    $query->select(DB::raw(1))
+                        ->from('followers')
+                        ->whereColumn('user_id', 'to_id')
+                        ->where('follower_id', $this->user->id);
+                });
         };
 
         return Question::query()