diff --git a/api/app/Observers/UserObserver.php b/api/app/Observers/UserObserver.php
new file mode 100644
index 00000000..d49ca296
--- /dev/null
+++ b/api/app/Observers/UserObserver.php
@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Observers;
+
+use App\Models\User;
+use App\Models\UserProfile;
+
+final class UserObserver
+{
+    /**
+     * Every user has exactly one user_profiles row. Created here so the
+     * profile exists the moment the user is saved — no matter the caller
+     * (seeder, invite flow, register, import, console command).
+     *
+     * Idempotent: firstOrCreate avoids collisions if another path already
+     * created the row (e.g. the populate migration during migrate:fresh).
+     */
+    public function created(User $user): void
+    {
+        UserProfile::firstOrCreate(['user_id' => $user->id]);
+    }
+}
diff --git a/api/app/Providers/AppServiceProvider.php b/api/app/Providers/AppServiceProvider.php
index 73747c15..027e81b6 100644
--- a/api/app/Providers/AppServiceProvider.php
+++ b/api/app/Providers/AppServiceProvider.php
@@ -38,6 +38,7 @@ use App\Models\FormBuilder\FormValue;
 use App\Models\VolunteerAvailability;
 use App\Observers\FormBuilder\FormValueObserver;
 use App\Observers\PersonObserver;
+use App\Observers\UserObserver;
 use Illuminate\Auth\Notifications\ResetPassword;
 use Illuminate\Database\Eloquent\Relations\Relation;
 use Illuminate\Support\ServiceProvider;
@@ -97,6 +98,7 @@ class AppServiceProvider extends ServiceProvider
         ]);
 
         Person::observe(PersonObserver::class);
+        User::observe(UserObserver::class);
         FormValue::observe(FormValueObserver::class);
 
         ResetPassword::createUrlUsing(function ($user, string $token) {
diff --git a/api/database/seeders/DevSeeder.php b/api/database/seeders/DevSeeder.php
index 2433ab4c..a07dc1db 100644
--- a/api/database/seeders/DevSeeder.php
+++ b/api/database/seeders/DevSeeder.php
@@ -20,6 +20,7 @@ use App\Models\TimeSlot;
 use App\Models\User;
 use App\Models\UserOrganisationTag;
 use App\Models\VolunteerAvailability;
+use App\Support\ActivityLog;
 use Illuminate\Database\Seeder;
 use Illuminate\Support\Collection;
 use Illuminate\Support\Facades\DB;
@@ -45,12 +46,17 @@ class DevSeeder extends Seeder
     {
         $this->call(RoleSeeder::class);
 
-        $this->seedOrganisation();
-        $this->seedEchtFeesten();
-        $this->seedBraderie();
-        $this->seedIJsbaan();
-        $this->seedKoningsdag();
-        $this->seedNachtVanDeKaap();
+        // Suppress all activity-log writes during bulk fixture generation.
+        // Hundreds of logSchemaChange/logFieldChange + Organisation-trait
+        // entries would otherwise flood activity_log without useful value.
+        ActivityLog::suppressed(function (): void {
+            $this->seedOrganisation();
+            $this->seedEchtFeesten();
+            $this->seedBraderie();
+            $this->seedIJsbaan();
+            $this->seedKoningsdag();
+            $this->seedNachtVanDeKaap();
+        });
     }
 
     // =========================================================================
@@ -152,11 +158,11 @@ class DevSeeder extends Seeder
                 $this->personTags[$data['name']] = $tag;
             }
 
-            // ── Registration Field Templates (system defaults) ──
+            // ── Form Builder: system templates (new structure) ──
 
-            \App\Services\RegistrationFieldTemplateService::seedSystemTemplates($this->org);
+            $templatesCreated = FormBuilderDevSeeder::seedSystemTemplates($this->org);
 
-            $this->command->info('  Organisation, 8 users, 6 companies, 7 crowd types, 10 person tags, 16 registration templates created');
+            $this->command->info("  Organisation, 8 users, 6 companies, 7 crowd types, 10 person tags, {$templatesCreated} form_templates created");
         });
     }
 
@@ -916,6 +922,10 @@ class DevSeeder extends Seeder
                 ]);
             }
 
+            $formSchema = FormBuilderDevSeeder::seedEventSchema($festival);
+            $submissions = FormBuilderDevSeeder::seedSubmissionsForEvent($festival, $formSchema);
+            $this->command->info("  Form schema + 16 fields + {$submissions} submissions created");
+
             $this->command->info('  Echt Feesten 2026 complete');
         });
     }
@@ -978,6 +988,10 @@ class DevSeeder extends Seeder
 
             $this->linkUsersToApprovedPersons($braderie);
 
+            $formSchema = FormBuilderDevSeeder::seedEventSchema($braderie);
+            $submissions = FormBuilderDevSeeder::seedSubmissionsForEvent($braderie, $formSchema);
+            $this->command->info("  Form schema + 16 fields + {$submissions} submissions created");
+
             $this->command->info('  Braderie Dorpstown 2026 complete');
         });
     }
@@ -1149,6 +1163,10 @@ class DevSeeder extends Seeder
 
             $personCount = Person::where('event_id', $ijsbaan->id)->count();
             $this->command->info("  {$personCount} persons, " . count($allShifts) . ' shifts created');
+
+            $formSchema = FormBuilderDevSeeder::seedEventSchema($ijsbaan);
+            $submissions = FormBuilderDevSeeder::seedSubmissionsForEvent($ijsbaan, $formSchema);
+            $this->command->info("  Form schema + 16 fields + {$submissions} submissions created");
         });
     }
 
@@ -1317,6 +1335,10 @@ class DevSeeder extends Seeder
             $personCount = Person::where('event_id', $koningsdag->id)->count();
             $assignCount = ShiftAssignment::whereIn('shift_id', collect($kShifts)->pluck('id'))->count();
             $this->command->info("  {$personCount} persons, 12 shifts, {$assignCount} assignments");
+
+            $formSchema = FormBuilderDevSeeder::seedEventSchema($koningsdag);
+            $submissions = FormBuilderDevSeeder::seedSubmissionsForEvent($koningsdag, $formSchema);
+            $this->command->info("  Form schema + 16 fields + {$submissions} submissions created");
         });
     }
 
@@ -1347,7 +1369,9 @@ class DevSeeder extends Seeder
 
             TimeSlot::create(['event_id' => $event->id, 'name' => 'Nacht', 'person_type' => 'VOLUNTEER', 'date' => '2026-09-12', 'start_time' => '20:00', 'end_time' => '04:00', 'duration_hours' => 8.00]);
 
-            $this->command->info('  Empty draft event created');
+            FormBuilderDevSeeder::seedEventSchema($event);
+
+            $this->command->info('  Empty draft event created (with form schema, 0 submissions)');
         });
     }
 
diff --git a/api/database/seeders/FormBuilderDevSeeder.php b/api/database/seeders/FormBuilderDevSeeder.php
new file mode 100644
index 00000000..e5a614cb
--- /dev/null
+++ b/api/database/seeders/FormBuilderDevSeeder.php
@@ -0,0 +1,231 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Seeders;
+
+use App\Enums\FormBuilder\FormFieldType;
+use App\Enums\FormBuilder\FormPurpose;
+use App\Enums\FormBuilder\FormSchemaSnapshotMode;
+use App\Enums\FormBuilder\FormSubmissionMode;
+use App\Enums\FormBuilder\FormSubmissionStatus;
+use App\Enums\FormBuilder\FormValueStorageHint;
+use App\Models\Event;
+use App\Models\FormBuilder\FormField;
+use App\Models\FormBuilder\FormSchema;
+use App\Models\FormBuilder\FormSubmission;
+use App\Models\FormBuilder\FormTemplate;
+use App\Models\FormBuilder\FormValue;
+use App\Models\Organisation;
+use App\Models\Person;
+use Illuminate\Support\Str;
+
+/**
+ * Seeds the form-builder layer for DevSeeder. Replaces the legacy
+ * RegistrationFieldTemplateService::seedSystemTemplates call — produces 16
+ * system form_templates per org, one FormSchema per event, canonical 16
+ * fields per schema, and a realistic set of FormSubmissions for
+ * approved/applied/no_show persons (matching the migration command rule).
+ *
+ * Callers MUST wrap this in ActivityLog::suppressed() — every field create
+ * would otherwise fire a logFieldChange("created") entry.
+ */
+final class FormBuilderDevSeeder
+{
+    /**
+     * 16 canonical registration fields mirroring the legacy system templates.
+     * Used by both seedSystemTemplates() and seedEventSchema() so the shape
+     * stays aligned.
+     *
+     * @return list<array<string, mixed>>
+     */
+    public static function canonicalFields(): array
+    {
+        return [
+            ['type' => FormFieldType::HEADING, 'slug' => 'persoonlijke-voorkeuren', 'label' => 'Persoonlijke voorkeuren', 'help_text' => 'Vertel ons wat we over jou moeten weten', 'display_width' => 'full'],
+            ['type' => FormFieldType::SELECT, 'slug' => 'shirtmaat', 'label' => 'Shirtmaat', 'options' => ['XS', 'S', 'M', 'L', 'XL', 'XXL', 'XXXL'], 'is_filterable' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::MULTISELECT, 'slug' => 'dieetwensen', 'label' => 'Dieetwensen', 'options' => ['Vegetarisch', 'Veganistisch', 'Halal', 'Glutenvrij', 'Lactosevrij', "Geen pinda's", 'Geen noten'], 'is_filterable' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::HEADING, 'slug' => 'vergoeding', 'label' => 'Vergoeding', 'help_text' => 'Kies hoe je wilt worden bedankt voor je inzet', 'display_width' => 'full'],
+            ['type' => FormFieldType::RADIO, 'slug' => 'vergoedingstype', 'label' => 'Vergoedingstype', 'options' => [
+                ['label' => 'Pro Deo', 'description' => 'Je werkt als vrijwilliger zonder financiële vergoeding'],
+                ['label' => 'Entreeticket', 'description' => 'Je ontvangt een gratis festivalticket als dank voor je inzet'],
+                ['label' => 'Vrijwilligersvergoeding', 'description' => 'Je ontvangt een vergoeding conform de vrijwilligersregeling'],
+            ], 'is_required' => true, 'display_width' => 'full'],
+            ['type' => FormFieldType::HEADING, 'slug' => 'noodcontact', 'label' => 'Noodcontact', 'help_text' => 'Wie kunnen we bereiken bij calamiteiten?', 'display_width' => 'full'],
+            ['type' => FormFieldType::TEXT, 'slug' => 'noodcontact-naam', 'label' => 'Noodcontact naam', 'is_pii' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::TEXT, 'slug' => 'noodcontact-telefoon', 'label' => 'Noodcontact telefoon', 'is_pii' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::HEADING, 'slug' => 'ervaring-vaardigheden', 'label' => 'Ervaring & vaardigheden', 'help_text' => "Welke diploma's en skills heb je?", 'display_width' => 'full'],
+            ['type' => FormFieldType::BOOLEAN, 'slug' => 'ehbo-bhv-diploma', 'label' => 'EHBO / BHV diploma', 'is_filterable' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::BOOLEAN, 'slug' => 'rijbewijs', 'label' => 'Rijbewijs', 'is_filterable' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::BOOLEAN, 'slug' => 'eerder-vrijwilliger-geweest', 'label' => 'Eerder vrijwilliger geweest', 'is_filterable' => true, 'display_width' => 'half'],
+            ['type' => FormFieldType::TAG_PICKER, 'slug' => 'certificaten-vaardigheden', 'label' => 'Certificaten & vaardigheden', 'is_filterable' => true, 'display_width' => 'full'],
+            ['type' => FormFieldType::HEADING, 'slug' => 'aanvullende-informatie', 'label' => 'Aanvullende informatie', 'display_width' => 'full'],
+            ['type' => FormFieldType::BOOLEAN, 'slug' => 'toestemming-gegevensverwerking', 'label' => 'Toestemming gegevensverwerking', 'help_text' => 'Ik geef toestemming voor de verwerking van mijn persoonsgegevens ten behoeve van de organisatie van dit evenement, conform de Algemene Verordening Gegevensbescherming (AVG).', 'is_required' => true, 'display_width' => 'full'],
+            ['type' => FormFieldType::TEXTAREA, 'slug' => 'opmerkingen', 'label' => 'Opmerkingen', 'display_width' => 'full'],
+        ];
+    }
+
+    public static function seedSystemTemplates(Organisation $org): int
+    {
+        $count = 0;
+        foreach (self::canonicalFields() as $sortOrder => $field) {
+            $snapshot = [
+                'schema_version' => 1,
+                'snapshot_created_at' => now()->toIso8601String(),
+                'schema' => [
+                    'name' => $field['label'].' (template)',
+                    'slug' => $field['slug'],
+                    'purpose' => FormPurpose::EVENT_REGISTRATION->value,
+                    'description' => null,
+                    'locale' => 'nl',
+                    'freeze_on_submit' => false,
+                    'section_level_submit' => false,
+                    'settings' => [],
+                ],
+                'sections' => [],
+                'fields' => [[
+                    'id' => (string) Str::ulid(),
+                    'slug' => $field['slug'],
+                    'field_type' => $field['type']->value,
+                    'label' => $field['label'],
+                    'help_text' => $field['help_text'] ?? null,
+                    'section_slug' => null,
+                    'options' => $field['options'] ?? null,
+                    'validation_rules' => null,
+                    'is_required' => $field['is_required'] ?? false,
+                    'is_filterable' => $field['is_filterable'] ?? false,
+                    'is_pii' => $field['is_pii'] ?? false,
+                    'binding' => null,
+                    'conditional_logic' => null,
+                    'translations' => null,
+                    'value_storage_hint' => $field['type']->recommendedValueStorageHint()->value,
+                    'sort_order' => $sortOrder + 1,
+                ]],
+            ];
+
+            FormTemplate::create([
+                'organisation_id' => $org->id,
+                'name' => $field['label'],
+                'slug' => $field['slug'],
+                'purpose' => FormPurpose::EVENT_REGISTRATION,
+                'description' => null,
+                'schema_snapshot' => $snapshot,
+                'is_active' => true,
+            ])->forceFill(['is_system' => true])->save();
+            $count++;
+        }
+
+        return $count;
+    }
+
+    /**
+     * Create one FormSchema (event_registration) for this event with the
+     * canonical 16-field set.
+     */
+    public static function seedEventSchema(Event $event): FormSchema
+    {
+        $schema = FormSchema::create([
+            'organisation_id' => $event->organisation_id,
+            'owner_type' => 'event',
+            'owner_id' => $event->id,
+            'name' => $event->name.' — registratie',
+            'slug' => Str::slug($event->slug.'-registratie'),
+            'purpose' => FormPurpose::EVENT_REGISTRATION,
+            'description' => "Registratieformulier voor {$event->name}.",
+            'is_published' => in_array(
+                $event->status,
+                ['registration_open', 'buildup', 'showday', 'teardown', 'closed'],
+                true
+            ),
+            'submission_mode' => FormSubmissionMode::DRAFT_SINGLE,
+            'locale' => 'nl',
+            'snapshot_mode' => FormSchemaSnapshotMode::NEVER,
+            'freeze_on_submit' => false,
+            'section_level_submit' => false,
+            'auto_save_enabled' => false,
+        ]);
+
+        foreach (self::canonicalFields() as $sortOrder => $field) {
+            FormField::create([
+                'form_schema_id' => $schema->id,
+                'field_type' => $field['type']->value,
+                'slug' => $field['slug'],
+                'label' => $field['label'],
+                'help_text' => $field['help_text'] ?? null,
+                'options' => $field['options'] ?? null,
+                'is_required' => $field['is_required'] ?? false,
+                'is_filterable' => $field['is_filterable'] ?? false,
+                'is_portal_visible' => true,
+                'is_admin_only' => false,
+                'is_pii' => $field['is_pii'] ?? false,
+                'display_width' => $field['display_width'] ?? 'full',
+                'value_storage_hint' => $field['type']->recommendedValueStorageHint(),
+                'sort_order' => $sortOrder + 1,
+            ]);
+        }
+
+        return $schema;
+    }
+
+    /**
+     * For each person with status ∈ applied/approved/no_show on this event,
+     * create one FormSubmission with a realistic handful of FormValues.
+     * Status follows the same rule as MigrateLegacyFormsData.
+     */
+    public static function seedSubmissionsForEvent(Event $event, FormSchema $schema): int
+    {
+        $fields = $schema->fields()->get()->keyBy('slug');
+        $persons = Person::where('event_id', $event->id)
+            ->whereIn('status', ['applied', 'approved', 'no_show'])
+            ->get();
+
+        $count = 0;
+        foreach ($persons as $person) {
+            $isSubmittedStatus = in_array($person->status, ['applied', 'approved', 'no_show'], true);
+            $status = $isSubmittedStatus ? FormSubmissionStatus::SUBMITTED : FormSubmissionStatus::DRAFT;
+
+            $submission = FormSubmission::create([
+                'form_schema_id' => $schema->id,
+                'subject_type' => 'person',
+                'subject_id' => $person->id,
+                'submitted_by_user_id' => $person->user_id,
+                'status' => $status,
+                'is_test' => false,
+                'submitted_in_locale' => 'nl',
+                'submitted_at' => $status === FormSubmissionStatus::SUBMITTED ? now()->subDays(rand(1, 30)) : null,
+                'schema_version_at_submit' => $status === FormSubmissionStatus::SUBMITTED ? 1 : null,
+            ]);
+
+            $seed = crc32((string) $person->id);
+            $sizes = ['XS', 'S', 'M', 'L', 'XL', 'XXL'];
+            self::createValueIfField($fields, 'shirtmaat', ['value' => $sizes[$seed % 6]], $submission);
+            self::createValueIfField($fields, 'dieetwensen', ($seed % 3 === 0) ? ['Vegetarisch'] : [], $submission);
+            self::createValueIfField($fields, 'rijbewijs', ['value' => ($seed % 2) === 0], $submission);
+            self::createValueIfField($fields, 'ehbo-bhv-diploma', ['value' => ($seed % 4) === 0], $submission);
+            self::createValueIfField($fields, 'noodcontact-naam', ['value' => 'Partner / Familielid'], $submission);
+            self::createValueIfField($fields, 'toestemming-gegevensverwerking', ['value' => true], $submission);
+
+            $count++;
+        }
+
+        return $count;
+    }
+
+    /**
+     * @param  \Illuminate\Support\Collection<string, FormField>  $fields
+     * @param  mixed  $value
+     */
+    private static function createValueIfField($fields, string $slug, $value, FormSubmission $submission): void
+    {
+        $field = $fields->get($slug);
+        if ($field === null) {
+            return;
+        }
+
+        FormValue::create([
+            'form_submission_id' => $submission->id,
+            'form_field_id' => $field->id,
+            'value' => $value,
+        ]);
+    }
+}