Re-add and use custom Twig extensions

src/Experience/TwigExtension/ExperienceTwigExtension.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace App\Experience\TwigExtension;
+
+use Sculpin\Contrib\ProxySourceCollection\ProxySourceItem;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFunction;
+
+class ExperienceTwigExtension extends AbstractExtension
+{
+    private static $startYear = 2007;
+
+    public function getFunctions(): array
+    {
+        return [
+            new TwigFunction('get_years_of_experience', [$this, 'getYearsOfExperience']),
+        ];
+    }
+
+    public function getName(): string
+    {
+        return 'experience';
+    }
+
+    public function getYearsOfExperience(): int
+    {
+        return (new \DateTimeImmutable())->format('Y') - self::$startYear;
+    }
+}