diff --git a/src/collaboration/services/ws-drain.service.ts b/src/collaboration/services/ws-drain.service.ts
new file mode 100644
index 00000000..57bbcf96
--- /dev/null
+++ b/src/collaboration/services/ws-drain.service.ts
@@ -0,0 +1,22 @@
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class WsDrainService {
+  private draining = false;
+  private readonly drainPeriodMs = 30000;
+
+  startDrain(): void {
+    this.draining = true;
+    setTimeout(() => {
+      this.draining = false;
+    }, this.drainPeriodMs);
+  }
+
+  isDraining(): boolean {
+    return this.draining;
+  }
+
+  canAcceptConnection(): boolean {
+    return !this.draining;
+  }
+}
diff --git a/src/payments/services/payment-enrollment-validator.service.ts b/src/payments/services/payment-enrollment-validator.service.ts
new file mode 100644
index 00000000..b804c1a7
--- /dev/null
+++ b/src/payments/services/payment-enrollment-validator.service.ts
@@ -0,0 +1,24 @@
+import { Injectable } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Repository } from 'typeorm';
+import { Payment } from '../entities/payment.entity';
+
+@Injectable()
+export class PaymentEnrollmentValidatorService {
+  constructor(
+    @InjectRepository(Payment)
+    private readonly paymentRepo: Repository<Payment>,
+  ) {}
+
+  async validateEnrollmentExists(enrollmentId: string): Promise<boolean> {
+    if (!enrollmentId) return true;
+    const result = await this.paymentRepo.query('SELECT id FROM enrollments WHERE id = $1', [enrollmentId]);
+    return result.length > 0;
+  }
+
+  async findOrphanedPayments(): Promise<Payment[]> {
+    return this.paymentRepo.query(
+      'SELECT p.* FROM payments p LEFT JOIN enrollments e ON e.id = p."enrollmentId" WHERE p."enrollmentId" IS NOT NULL AND e.id IS NULL',
+    );
+  }
+}