5 Hidden Failure Modes When Routing Between 10+ LLM Providers in 2026

Routing between multiple LLM providers in 2026 can lead to unexpected failure modes due to behavioral differences and format drift. These failure modes can be subtle and require validation and sanitization of responses before parsing. To mitigate this, use a resilient JSON extractor that strips code fences and attempts trailing comma repair. Additionally, provider-specific post-processing rules may be necessary to catch remaining format drift. This requires ongoing maintenance per-provider.