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Q77: How Do You Perform Load Testing for Web APIs?

📈Core Concept

How Do You Perform Load Testing for Web APIs?

Key Takeaways & Architecture Summary

✓Use load engines like k6, JMeter, or Gatling to execute load.
✓Define load scenarios, ramp-up speeds, and maximum user stress.
✓Track system thresholds (throughput, latency, error percentages).

Direct Answer Summary

Load testing involves simulating concurrent user traffic using tools like k6, JMeter, or Gatling. You define test scenarios (ramp-up periods, steady-state load, and ramp-down phases) and execute requests, monitoring performance indicators like throughput (RPS), error rates, and CPU metrics.

⚠️ Senior Engineering Warning (Red Flag)

Never run load tests against production databases without coordinate approvals and active backups. Load runs can starve database connection pools, crashing services for customers.

💡 STAR Architectural Explanation & Pro Tip

Load testing exposes structural limits like database deadlock loops, microservice memory leaks, or load balancer configurations that function fine under light developer checks but fail under load.

RestAssuredTest.java

Rest-Assured + Java

// k6 performance script: Simulate 50 concurrent users
import http from 'k6/http';
import { check, sleep } from 'k6';

export const options = {
  vus: 50, // Virtual Users count
  duration: '30s',
};

export default function () {
  const res = http.get('https://api.careerraah.com/v1/jobs');
  check(res, { 'status is 200': (r) => r.status === 200 });
  sleep(1);
}