Backend QA Engineer

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Backend QA Engineer based in Spain. Take ownership of quality across a high-traffic, backend-focused platform where reliability and precision are critical. You’ll combine hands-on manual testing with automation to validate APIs, transaction lifecycles, data, and event-driven services. The role gives you the opportunity to uncover edge cases and risks beyond what is explicitly defined in specifications. You’ll work closely with engineers and other stakeholders to ensure robust releases and prevent critical issues from reaching production. Your work will span REST and gRPC APIs, relational databases, message queues, and distributed backend services. You’ll also contribute to automated regression coverage using Go and help continuously strengthen the testing approach. Working fully remotely within a global team, you’ll have meaningful ownership in a fast-growing technology environment. Accountabilities

• Analyze business requirements, functional specifications, and user stories to design comprehensive test cases, scenarios, and coverage strategies.
• Perform end-to-end testing of transaction lifecycles, including initiation, authorization, settlement, reconciliation, and related workflows.
• Proactively explore the platform to identify edge cases, unexpected behavior, risks, and gaps not covered by existing specifications.
• Validate data accuracy, integrity, and consistency across services using SQL queries against PostgreSQL and MySQL.
• Test REST and gRPC APIs using tools such as Postman, grpcurl, or equivalent solutions, validating requests, responses, error handling, and edge cases.
• Verify event-driven workflows across message brokers such as Kafka, RabbitMQ, and NATS, including retries, failures, ordering, and duplicate-message handling.
• Write, maintain, and extend automated regression tests in Go, collaborating with developers when additional test coverage or technical support is required.
• Log, prioritize, track, and manage defects in Jira, providing clear reproduction steps, payloads, logs, and relevant technical context.
• Execute regression testing following deployments and help ensure releases meet expected quality standards.
• Contribute to improving QA processes, automation coverage, and overall testing efficiency across the platform.

• 4+ years of professional manual testing experience, with a strong focus on backend services, APIs, and distributed systems.
• Previous experience testing products in iGaming, fintech, payment gateways, banking, or another transaction-intensive domain.
• Strong proficiency in writing intermediate SQL queries for validating and investigating data in relational databases.
• Hands-on experience with API testing tools, particularly Postman, as well as test management platforms such as TestRail or Zephyr.
• Ability to read Go code and write or extend automated tests in Go; previous automation experience in another programming language is acceptable if you are willing to work with Go.
• Working knowledge of Docker and the ability to run and test services locally.
• Solid understanding of Agile/Scrum methodologies and the Software Testing Life Cycle (STLC).
• Strong analytical and problem-solving abilities, combined with meticulous attention to detail.
• Experience with microservices architectures and backend systems is highly valuable.
• Familiarity with CI/CD pipelines, Kubernetes, or observability and monitoring tools is a plus.
• Experience supporting User Acceptance Testing (UAT) with business stakeholders is an advantage.
• Existing professional experience with Go and/or Playwright is considered a plus.
• Strong communication and collaboration skills, with the ability to work effectively with engineering and business teams in a fully remote environment.

• Fully remote work with a globally distributed team.
• Full-time opportunity within a fast-growing technology environment.
• The opportunity to help build and scale a B2B platform from the ground up within a newly established technology ecosystem.
• Collaboration with teammates and technical professionals from around the world.
• Up to 28 unavailable days per year, in addition to public holidays.
• Significant ownership and the opportunity to shape quality practices across a high-traffic platform.
• Exposure to modern backend technologies, distributed systems, APIs, event-driven architectures, and automated testing.
• An environment where engineering quality, initiative, and proactive problem-solving are highly valued.