Building Resilient LLM Applications with Fallback Strategies

Why Fallbacks Matter

LLM providers experience outages. A resilient system continues serving users even when primary providers fail.

Fallback Chain Design

const modelChain = [
  { model: "qwen-max", provider: "Alibaba" },
  { model: "deepseek-v3", provider: "DeepSeek" },
  { model: "glm-4", provider: "Zhipu" },
  { model: "ernie-4", provider: "Baidu" }
];

async function callWithFallback(prompt) {
  for (const { model, provider } of modelChain) {
    try {
      const response = await callModel(model, prompt);
      return response;
    } catch (e) {
      if (isRecoverable(e)) continue;
      throw e;
    }
  }
}

Graceful Degradation

If all models fail, return cached responses or a friendly error message. Never expose raw errors to users.

Health Monitoring

Track provider health in real-time. Automatically route around unhealthy providers using circuit breakers.