API Integration Test Engineer

About the Position

We are looking for an API Integration Test Engineer who makes API quality their craft. You will be a specialist responsible for API and integration test coverage across the program, designing test suites, owning CI/CD quality gates, and tracing data consistency end to end across interconnected systems. The role requires working from the office three days per week. The candidate should be based in either Cluj Napoca or Bucharest.

About the Project

The program involves extensive API integration work across SOAP to REST migrations, Kafka based event pipelines, WebSocket real time feeds, and multi system data flows. DataArt squads are embedded within client delivery teams, working fully remotely across the EU and using Scrum.

Responsibilities

• Design and implement API test suites, including REST contract validation, JSON schema checks, and negative path coverage.
• Validate event driven integrations, including Kafka consumer validation, message ordering, deduplication, and data consistency.
• Test WebSocket feeds for connection stability, message sequencing, and data accuracy under load.
• Validate SOAP to REST migration parity, ensuring that legacy and new responses are semantically equivalent.
• Integrate all test suites into CI/CD pipelines and create quality gates that prevent defective releases.
• Trace data across systems using SQL and verify end to end consistency.

Requirements

• 5+ years of experience in software testing, specializing in API and integration testing.
• Strong hands on coding experience with Python (Requests, Pytest) and/or Java (REST Assured).
• Experience with REST API testing, including HTTP semantics, authentication (OAuth, API keys, JWT), and contract testing.
• Experience testing Kafka and other messaging systems, including consumer validation, offset management, and schema registries.
• Experience testing WebSocket applications, including connection lifecycle management, message framing, and reconnect behavior.
• Strong SQL skills, including complex queries, multi table joins, and data tracing.
• Experience with JSON and XML manipulation, including the ability to compare large payloads programmatically.
• Proficient English for technical communication (B2+).

Nice to Have

• Experience in the financial services or capital markets domain.
• Exposure to the gRPC protocol.
• Experience with API level performance testing tools such as Locust, k6, or Gatling.
• Familiarity with SOAP and WS Security testing.