Consider using explicit property syntax for clarity: { jefeMecanicoId: jefeMecanicoId }
The default parameter db = prisma works because PrismaClient satisfies TransactionClient, but add a comment to clarify this intentional covariance for future maintainers.
Function name 'yaProcesado' suggests it returns true if already processed, but it returns false on successful insert (new message). Consider renaming to 'registrarProcesado' or inverting logic for clarity.
Header 'x-hub-signature-256' may be undefined; firmaValida should handle missing header explicitly or check here before calling.
Fire-and-forget with empty catch hides potential issues marking messages as read; at least log the error for observability.
Catch-all returns 200 to avoid Meta retries, but errors are only logged. Add alerting/monitoring (e.g., Sentry) so failures don't go unnoticed.
Module-level variable 'ultimaLimpieza' is not reliable in serverless/multi-instance environments; each instance has its own memory and cold starts reset it. Consider a cron job or DB-based cleanup instead.
Cleanup runs on every POST request adding latency; with the unreliable timer it may run too often or not at all. Move to a scheduled job (e.g., Vercel Cron) or a separate background worker.
Type assertion without runtime validation; if Meta changes payload structure this will fail silently. Use a schema validator (e.g., zod) to parse and validate the webhook payload.