Senior QA Automation Engineer - API & Billing (Remote)

UST; Spain (TX); On-site; EUR 42,000 - 65,000; Full time

Benefits offered by this job

Annual Leave 23 days + discretionary 2

Health and life insurances

Training platforms access

Career stability and growth

Remote work policy & flexible hours

Referral bonuses

Payment frequency options

Work-life balance initiatives

Job summary

UST is a multinational technology company seeking a QA/Test Engineer to join our enterprise software QA team, focusing on billing, CRM, ERP, and data validation. You will design test strategies, execute functional and API tests, and contribute to automation and CI/CD efforts.

We value strong English communication and 4+ years of experience, with exposure to testing frameworks and modern tools. This role offers full remote work with occasional travel to London, UK.

Qualifications

• 4+ years of experience in software testing within enterprise environments.
• Strong knowledge of functional, integration, API, and end-to-end testing.
• Experience with test automation, SQL, and CI/CD pipelines.
• Experience with billing, pricing, or financial validation is a plus.

Responsibilities

• Define and execute test strategies, plans, estimates, coverage models, and quality gates aligned with project risks and delivery milestones.
• Design and execute functional, integration, end-to-end, API, regression, exploratory, and data validation test scenarios.
• Validate billing, invoicing, payments, refunds, collections, and financial processes across the platform.
• Perform complex billing verification, including proration, effective dating, taxes, discounts, adjustments, reversals, rebilling, and exception handling.
• Test APIs and event-driven integrations, ensuring reliability, sequencing, idempotency, error handling, and operational visibility.
• Develop and maintain automated tests and regression suites for APIs, services, and critical business journeys.
• Use SQL for data setup, validation, comparison, migration verification, and reconciliation activities.
• Prepare and manage test environments, test data, customer accounts, meters, tariffs, and usage scenarios.
• Log, track, analyze, and retest defects while collaborating with developers, analysts, and business stakeholders.
• Support User Acceptance Testing (UAT) through scenario preparation, execution monitoring, evidence collection, and defect management.
• Contribute to performance, resilience, security, and operational readiness testing activities.
• Support cutover rehearsals, production validation, smoke testing, reconciliation controls, and hypercare activities.

Skills

End-to-End Testing

Functional Testing

Integration Testing

Regression Testing

Risk-Based Testing

API Testing

SQL

Test Automation

Cucumber

Selenium

CI/CD

Financial & Billing Validation

Education

ISTQB or equivalent testing certification

Tools

Postman

REST Assured

JUnit

Selenium

JMeter

k6

Gatling

AWS

Job description

UST is a multinational technology company seeking a QA/Test Engineer to join our enterprise software QA team, focusing on billing, CRM, ERP, and data validation. You will design test strategies, execute functional and API tests, and contribute to automation and CI/CD efforts.

We value strong English communication and 4+ years of experience, with exposure to testing frameworks and modern tools. This role offers full remote work with occasional travel to London, UK.