Scaling Captcha Infrastructure to 1 Billion Requests

Handling a billion requests isn't just about adding more servers—it's about fundamentally rethinking how you handle state, concurrency, and routing.

The Challenge

At CaptchaSonic, our primary metric is Time-to-Solve (TTS). When a detailed CAPTCHA challenge arrives, every millisecond counts.

Our Architecture

We moved from a monolithic queue to a partitioned, region-aware dispatch system.

1. Geo-DNS Routing

Traffic is routed to the nearest edge node.

2. Edge Processing

Requests are validated and sanitized at the edge using Cloudflare Workers.

3. Solver Mesh

Our custom "Solver Mesh" dynamically allocates browser instances based on difficulty scoring.

// Simplified logic of our dispatcher
async function dispatchJob(job: Job) {
  const complexity = analyzeComplexity(job.payload);
  const region = await getOptimalRegion(job.origin);
  
  return solverMesh.assign(region, complexity, job);
}

Results

Since implementing the new mesh architecture, we've seen:

• 99.99% Uptime over the last quarter.
• 40% Reduction in cloud costs due to smarter resource allocation.