The Problem: Fraud Scoring Was a Latency Bottleneck in the Authorization Path

Palisade Pay’s corporate card platform calls an LLM-assisted fraud-scoring model synchronously during transaction authorization, meaning the model’s response time is directly added to the card-network authorization window, which is capped at 50ms by network partner SLAs. The legacy model-serving stack, a self-hosted Triton deployment behind a generic load balancer, averaged 38ms P50 but spiked to 210ms P99 under load, occasionally forcing authorization timeouts that defaulted to manual review.

The core problem was that the serving layer had no request-priority awareness: a batch reconciliation job’s inference requests competed for the same queue as time-critical authorization requests. There was no mechanism to guarantee latency-sensitive traffic preferential scheduling.

The Implementation: Meridian Priority-Aware Inference Gateway

Palisade Pay deployed the Meridian Inference Gateway in front of their existing model artifacts, using its priority-queue scheduler to classify requests at ingestion. Authorization-path requests are tagged with a hard 15ms SLA and routed to a dedicated low-latency worker pool with pinned memory and warm model weights; batch and reconciliation traffic is routed to a separate best-effort pool.

Separating the latency-critical path from everything else sounds obvious in hindsight, but our original stack genuinely had no concept of request priority. Meridian gave us that primitive without requiring a model rewrite.

The gateway also maintains active health checks against each worker pool independently, so a degraded batch pool cannot starve the authorization pool of compute, a failure mode the legacy shared-queue architecture was structurally exposed to.

Results: Measured Infrastructure Impact

Authorization-path inference latency now sits at under 15ms at P99, comfortably inside the 50ms network SLA window with headroom for network transit time. Gateway uptime over the trailing 12 months measured 99.992%, and manual-review fallbacks triggered by authorization timeout dropped to fewer than 3 per month, down from a prior average of 210.