Abstract : Enterprise traffic engineering architectures depend on the coordinated operation of DNS-based global routing and load balancer-based application delivery to maintain service continuity under infrastructure failure conditions. Conventional approaches implement these two tiers as independent systems, each making routing decisions without real-time visibility into the other's operational state a structural gap that produces capacity mismatches and multi-hour service disruptions precisely when coordinated response is most critical. This article presents an adaptive dual-layer traffic engineering framework designed for enterprise environments where application availability is operationally non-negotiable. The framework integrates an intelligent DNS routing tier implemented through platforms such as F5 GTM and Infoblox DNS Traffic Control with a load balancer tier through a continuous cross-layer health synchronization bridge. A composite health scoring model quantifies data center operational state across four signal dimensions: backend server availability, application response latency, network health, and platform stability. This model enables graduated, proportional DNS traffic weight adjustments that reflect real-time capacity conditions rather than binary healthy/unhealthy states. A phased traffic restoration protocol governs recovery sequencing to prevent recovery-triggered re-failure a failure mode more consequential than is commonly recognized in post-incident analyses. The framework is evaluated against four major documented enterprise failures the 2012 AWS US-East-1 regional degradation, the 2021 Meta global BGP outage, the 2022 Cloudflare anycast control-plane failure, and the 2024 CrowdStrike platform-specific endpoint crisis each exposing a distinct architectural gap that the proposed framework addresses. Empirical performance data from enterprise deployments demonstrates mean time to recovery reductions of 50–65%, critical failover completion in under 2 minutes, and a 70% reduction in manual operational interventions per incident. Resilient traffic engineering, the evidence establishes, is an architectural property of coordinated cross-layer design not a consequence of hardware investment.