StoneX Ltd is an FCA authorised and regulated firm to provide trade execution, clearing and advisory services focusing primarily on the Commodities and Foreign Exchange sectors. 

StoneX Ltd is part of the StoneX Inc. which is a Fortune 500 company, providing customers across the globe with services including execution and advisory services in Commodities, Capital Markets, Currencies and Asset Management.  

OUR TEAM 

We operate globally from offices in Europe, US and Asia Pacific. Our employees work closely together in multidisciplinary teams, making our success possible. 

Technology - At StoneX, technology is at the heart of everything we do. Our technologists push the limits of possibility, embracing the right technology that adds value to our business. In our fast-paced environment, short feedback loops collaborating with our business partners allows us to deliver projects into production quickly. 

Focus – Our teams are business aligned developing and supporting complex solutions across Trading, Risk, Compliance and Operations. 

We are seeking a skilled and detail-oriented Senior QA Engineer to join our Backend Core Team. This role focuses on validating the quality and reliability of backend services, especially gRPC and REST APIs. You’ll work closely with developers, DevOps and product teams to design test strategies, implement automation, and ensure the stability of critical backend components. 

Key Responsibilities: 

• Design, develop, and maintain automated tests for backend services, including gRPC and REST APIs. 

• Create and execute test plans, test cases, and test scripts covering functional, regression, integration, and performance scenarios. 
• Manage the creation and execution of test cases using TestRail, and generate comprehensive regression reports along with test coverage metrics.

• Collaborate with backend engineers to understand system design and ensure thorough test coverage across microservices. 

• Implement mocking, contract testing, and service simulation strategies for dependent services. 

• Extend and maintain test automation frameworks using mocha or similar tools (e.g., vitest) tailored for backend and integration testing. 

• Integrate automated tests into CI/CD pipelines to ensure quick feedback and high confidence in releases. 

• Analyze test failures, troubleshoot issues, and contribute to root cause analysis and resolution. 

• Work with stakeholders to establish quality KPIs and continuously improve testing practices and coverage. 

• Mentor junior QA team members on backend testing techniques, tooling, and best practices. 

Requirements: 

Must-Have: 

• 3-4 years of hand-on experience in automation QA engineering, with a strong focus on backend testing and API validation. 

• Hands-on experience testing gRPC services using tools such as Kreya, gRPCurl, or Postman for gRPC. 

• Strong understanding of REST API testing, including status codes, payload validation, authentication, and error handling. 

• Solid scripting/programming skills in TypeScript, JavaScript, Python, or similar. 

• Proficient with Playwright or comparable automation tools (e.g., Cypress, Supertest, RestAssured) used in backend or integration testing contexts. 
• Manage end-to-end defect lifecycle in Jira, including logging, triaging, prioritization, and tracking defects to closure in collaboration with development teams.

• Experience working with CI/CD tools such as GitHub Actions, GitLab CI, or Jenkins. 

• Knowledge of contract testing frameworks (e.g., Pact) and mocking techniques. 

• Familiarity with microservice architecture and inter-service communication patterns. 

• Excellent debugging, problem-solving, and communication skills. 

Nice-to-Have: 

• Experience testing event-driven systems, e.g., Kafka, RabbitMQ. 

• Knowledge of performance testing tools such as k6, JMeter, or Locust. 

• Exposure to Docker, Kubernetes, and testing within containerized environments. 

• Experience with observability tools (e.g., Prometheus, Grafana, ELK Stack). 

• Domain knowledge in FinTech, trading systems, or other regulated industries.