Senior SDET – (India)

Welo Data, part of Welocalize, operates as a global AI data company with over 500,000 contributors across 100+ countries. The organization focuses on delivering high-quality, ethical data to train advanced AI systems, emphasizing human contribution in building smarter, more responsible AI. They work with a distributed community model that prioritizes flexibility and meaningful work across diverse projects.

You'll join the Welo Data team as a Senior SDET on a five-week freelance engagement (with potential for full-time conversion based on performance). This is a remote contractor role based in India, requiring 33 hours per week at a rate of $13.50 per hour, starting October 19.

Your focus will be testing the resilience and correctness of distributed backend systems that power account provisioning and onboarding workflows. You'll execute pre-approved, benign tracer and replay scenarios against staging endpoints, then analyze request and response patterns to document observable account and CID lifecycle behavior. This role involves technical investigation, not unrestricted adversarial testing—all activities remain within approved staging environments using pre-approved scenarios.

What you'll do

• Analyze distributed system APIs across account creation, data persistence, and record-linking services to validate correctness, consistency, and failure handling
• Execute pre-approved request variations and boundary-validation scenarios using sanitized tracer payloads against designated staging endpoints
• Capture complete request/response evidence including HTTP status codes, latency, headers, and payload bodies according to approved data-handling requirements
• Validate behavior of inline checks evaluated at the gateway (millisecond scale) versus longer-running background verification and risk pipelines (minute to hour scale)
• Verify data persistence, referential integrity, and correct linkage of related records written by backend services
• Execute controlled replay suites and compare expected versus observed API behavior, correlating results with API schemas and network evidence
• Collaborate with backend engineering teams to reproduce, isolate, and validate fixes for distributed-system defects
• Maintain traceability between test evidence, defects, and system requirements through structured documentation and log archival

What you'll bring

• Five to eight or more years testing distributed systems and analyzing inter-service API behavior
• Hands-on experience with request payload tampering, fuzzing, or adversarial API testing techniques
• Deep understanding of layered defense architectures and the distinction between synchronous inline validation and asynchronous background verification
• Demonstrated discipline in test log archival, evidence capture, and structured documentation practices
• Solid understanding of backend and middleware architecture, failure modes, and system boundaries
• Familiarity with API testing tools and scripting capabilities for custom fuzzing and tampering test cases
• Strong analytical skills for root-causing complex, systemic defects

Nice to have

• Experience executing controlled API replay or staging validation
• Ability to correlate API responses with observable application and account lifecycle states
• Background supporting audit, compliance, or evidence-based reporting requirements