Why should you care?

SaaS revenue requires isolating tenant data and enforcing plan limits on API usage.

See it live — copy this example

Paste into your MeanVerse project (Angular + Express + MongoDB), then run with ng serve / node / mongosh as noted.

// meanverse-saas/
//   api/src/middleware/tenant.middleware.ts
//   web/src/app/core/tenant/tenant.service.ts

export function resolveTenant(req: Request, _res: Response, next: NextFunction) {
  const tenantId = req.headers['x-tenant-id'] as string;
  if (!tenantId) return next(new AppError(400, 'Tenant required'));
  req.tenantId = tenantId;
  next();
}

@Injectable({ providedIn: 'root' })
export class TenantService {
  private http = inject(HttpClient);
  current = signal<Tenant | null>(null);
  load() { return this.http.get<Tenant>('/api/saas/tenant/me').pipe(tap(t => this.current.set(t))); }
}

What happened?

• Middleware reads X-Tenant-Id on every request.
• Mongo queries filter { tenantId }.
• Angular TenantService loads current tenant for UI branding and limits.

Practice next

1. Add tenantId to all Mongoose schemas and indexes.
2. Middleware rejects requests without tenant context.
3. Integrate Stripe subscription webhooks.
4. Add usage counter increment middleware per API call.
5. White-label Angular theme from tenant.settings.

Remember

SaaS = tenant isolation + billing + admin. Header or subdomain resolves tenant. Enforce plan limits in middleware.

HR software vendor

2000 companies on one MeanVerse deploy; each sees only their employees.

Outcome: Tenant middleware + indexes pass SOC2 isolation audit.