Backend QA Engineer: API Automation & Release Validation

Horizontal Talent; Foster City (CA); On-site; USD 30,000 - 52,000; Full time

Job summary

Horizontal Talent is seeking a detail-oriented QA Engineer to build automation, validate releases, and improve product quality across backend services and microservices in an onsite environment.

You will design automated tests for APIs, validate deployment readiness, and extend performance tests using K6/Locust, while integrating checks into CI/CD pipelines and collaborating with engineering teams.

Qualifications

• Strong proficiency in Python and/or TypeScript for test automation, API testing, and data validation.
• Hands-on experience with REST API testing frameworks such as pytest and requests, or similar tools.
• Experience with schema validation and API contract verification.
• Knowledge of performance and load testing tools such as K6, Locust, or equivalent.
• Ability to write SQL queries for quality metrics, release analysis, and issue triage.
• Experience working with Git, code reviews, and CI systems.
• Comfort troubleshooting distributed services in containerized environments using logs, health checks, and basic cluster tooling.
• Strong written and verbal communication skills with a collaborative approach to problem-solving.

Responsibilities

• Design, build, and maintain automated test coverage for backend APIs, background workers, and related microservices across multiple environments.
• Support release validation for versioned service deployments and help confirm readiness before production rollout.
• Create and extend performance and load tests for REST APIs using tools such as K6 or similar solutions.
• Integrate automated checks into CI/CD pipelines and release workflows to improve repeatability and speed of validation.
• Verify critical release behavior, including data consistency, schema changes, API contract updates, and cross-service interactions.
• Perform exploratory and component-level testing for new functionality and defect fixes, then help triage issues with engineering teams.
• Monitor release health through dashboards, logs, and test results to identify trends and possible regressions.
• Partner with engineering and QA stakeholders to define release criteria, test plans, and long-term automation approach.
• Document testing strategy, pipeline logic, and validation steps to support maintainability and knowledge sharing.

Skills

Python

TypeScript

API testing

pytest

requests

Schema validation

API contract verification

Performance testing

SQL

Git & CI

Troubleshooting distributed systems

Communication

Tools

K6

Locust

CI/CD pipelines

Job description

Horizontal Talent is seeking a detail-oriented QA Engineer to build automation, validate releases, and improve product quality across backend services and microservices in an onsite environment.

You will design automated tests for APIs, validate deployment readiness, and extend performance tests using K6/Locust, while integrating checks into CI/CD pipelines and collaborating with engineering teams.