Powerful Developer Workflows with Sequential Thinking

Prompt:
Use Sequential Thinking MCP server to investigate why our app's authentication is failing intermittently in production. Research possible causes, identify patterns in error logs, and determine if it's related to our recent API integration or infrastructure changes.

Output:
Thought 1 (Define Goal): Research intermittent authentication failures in production. Need to examine logs, recent changes, and identify patterns.

Thought 2 (Research - Error Logs): Analyzing production logs... Found repeated 401 errors with consistent pattern: occurring during peak traffic hours (11am-1pm), primarily affecting users with JWT tokens older than 30 minutes.

Thought 3 (Research - Recent Changes): Examining recent deployments... Identified two potential factors: 1) API rate limiting added to auth provider two weeks ago, 2) Load balancer configuration changed last week.

Thought 4 (Investigation - Auth Flow): Tracing authentication flow... Discovered an edge case where token refresh calls don't properly handle 429 responses from auth provider, causing cascading auth failures during high traffic.

Thought 5 (Investigation - Infrastructure): Checking load balancer configuration... Found connection pooling settings causing requests to be dropped when connections exceed threshold, which coincides with peak traffic periods.

Thought 6 (Root Cause Analysis): Primary issue: Auth service not implementing proper backoff/retry logic when receiving rate limit responses. Secondary issue: Load balancer connection pool size insufficient for peak traffic.

Thought 7 (Solution Recommendations):
1. Implement exponential backoff for token refresh operations
2. Add proper error handling for 429 responses
3. Increase load balancer connection pool limits by 40%
4. Add monitoring alert for auth failure rate exceeding 0.5%

Thought 8 (Documentation): Created incident analysis document highlighting root causes and solution path. Added code example showing proper implementation:

```typescript
// auth-service.ts
async function refreshToken(token: string): Promise<AuthResponse> {
  const maxRetries = 3;
  let retryCount = 0;
  
  while (retryCount < maxRetries) {
    try {
      const response = await fetch(AUTH_ENDPOINT, {
        method: 'POST',
        headers: { 'Authorization': `Bearer ${token}` }
      });
      
      if (response.status === 429) {
        // Calculate backoff time: 2^retry * 100ms + random jitter
        const backoffMs = (Math.pow(2, retryCount) * 100) + 
                          (Math.random() * 100);
        await new Promise(resolve => setTimeout(resolve, backoffMs));
        retryCount++;
        continue;
      }
      
      return await response.json();
    } catch (error) {
      if (isRetryableError(error) && retryCount < maxRetries) {
        retryCount++;
        continue;
      }
      throw error;
    }
  }
  
  throw new Error('Max retries exceeded for token refresh');
}