API Testing Demo

Overview

This project shows how I approach backend quality when both correctness and responsiveness matter. It uses a local synthetic HTTP service and a Maven-based test suite to validate service health, compare endpoint responses against an expected contract, and assert simple performance baselines such as average response time and p95. The result is a lightweight but concrete example of introducing API quality signals without building a separate integration environment first.

Challenge

1. 01

   Backend teams often validate correctness and performance in separate tools and at separate points in the delivery process.

2. 02

   Even small services need confidence around contracts and response-time expectations, but teams may not have a dedicated shared test environment.

3. 03

   Portfolio examples should demonstrate realistic backend verification while staying safe and fully local.

4. 04

   Quality signals are more useful when they are cheap to run and easy to understand for both engineers and stakeholders.

Approach

1. 1

   Built a local HTTP service with synthetic responses to keep the full validation loop self-contained and reproducible.

2. 2

   Added a health check test to verify service availability and a contract test to compare payloads with an expected JSON structure.

3. 3

   Implemented a simple performance baseline using repeated requests and assertions on average latency and p95.

4. 4

   Used standard Java and Maven tooling so the project looks and behaves like a small, CI-ready backend quality suite.

5. 5

   Kept the setup intentionally lightweight to show how useful signals can be introduced without heavy infrastructure overhead.

Outcomes

• Demonstrates a combined correctness-and-performance view of API quality in one compact suite.

• Shows how contract validation and latency guardrails can be introduced without dedicated external environments.

• Provides a clear, repeatable example of backend quality engineering that is easy to run in CI.

• Keeps the demo safe and public-ready by relying only on local synthetic service behavior.

Summary

API quality is strongest when correctness and responsiveness are validated together. This demo shows a lightweight path to that combined signal using only local, reproducible assets.