Senior SDET – (India)

Job Overview 
We are looking for a Senior SDET to test the resilience and correctness of distributed backend systems supporting a high-stakes account provisioning and onboarding workflow. This role is focused on the execution of pre-approved, benign tracer/replay scenarios against staging endpoints, analysis of request/response behaviour, and documentation of observable account/CID lifecycle and downstream state behaviour. 
The ideal candidate has strong distributed-systems and API-testing experience and maintains disciplined technical evidence capture and traceability. 
This role is not intended to perform unrestricted adversarial testing. Testing activities will be limited to approved staging environments and pre-approved benign scenarios.

Project Details
Title: Senior SDET
Rate: $13.5/hr 
Start Date: 19th October
Duration: 5 Weeks
Commitment: 33 Hours per Week
Location: India (Remote)
Job Type: Freelance

Responsibilities

- Analyze distributed system APIs to validate correctness, consistency, and failure handling across services involved in account creation, data persistence, and related record-linking

- Execute pre-approved request variations and boundary-validation scenarios using sanitized tracer payloads against designated staging endpoints.

- Investigate system behavior under malformed, malicious, or unexpected inputs and document findings clearly

- Capture complete request/response evidence, including HTTP status codes, latency, headers, and payload bodies, subject to approved data-handling requirements.

- Validate behavior of near-real-time inline checks (evaluated within milliseconds at the gateway) as distinct from longer-running background verification/risk pipelines (evaluated over minutes to hours), confirming each layer of defense behaves as expected

- Verify data persistence, referential integrity, and correct linkage of related records/relationships written by backend services during processing

- Execute controlled replay suites and compare expected versus observed API behavior.

- Correlate replay results with the API schemas and network evidence produced by the Middleware SDET.

- Document observable account/CID lifecycle behavior and downstream state changes for handoff

- Capture and archive test logs and evidence in a structured, retrievable format to support audits and post-incident reviews

- Collaborate with backend engineering teams to reproduce, isolate, and validate fixes for distributed-system defects

- Contribute to test strategy for backend/middleware reliability, including failure-mode and chaos-style testing

- Maintain traceability between test evidence, defects, and system requirements

- Reconcile backend observations with the frontend FSM and middleware/API evidence produced by earlier workstreams.

Required Qualifications

- Strong experience of 5-8+ years in testing distributed systems and analyzing inter-service API behavior

- Hands-on experience with request payload tampering, fuzzing, or adversarial API testing techniques

- Understanding of layered defense architectures, including the distinction between synchronous/inline validation and asynchronous/background verification processes

- Familiarity with testing data persistence and relational/hierarchical integrity in backend data stores

- Demonstrated discipline in test log archival, evidence capture, and structured documentation practices

- Solid understanding of backend/middleware architecture, failure modes, and system boundaries

- Familiarity with API testing tools and scripting for building custom fuzzing/tampering test cases

- Strong analytical and investigative skills for root-causing complex, systemic defects

- Experience executing controlled API replay or staging validation is strongly preferred.

- Experience correlating API responses with observable application/account lifecycle states is preferred.

- Experience supporting audit, compliance, or evidence-based reporting requirements is a plus

Why join Welo Data?  
✨ Limitless Flexibility: Work on projects that fit your schedule while collaborating with a global leader in AI data services and localization.  
🌱 Limitless Growth: Apply your skills, access diverse content types, develop through structured learning, and explore career paths that can lead to permanent roles.  
🌍 Limitless Support: Be part of a global community with real-time assistance from our Community Experience team.  
 
How to Apply? 
Apply now by answering a few quick questions to join our database and become part of our growing community.  
 
We can’t wait to meet you!  
 
About Welo Data

Welo Data, part of Welocalize, is a global AI data company with 500,000+ contributors delivering high-quality, ethical data to train the world’s most advanced AI systems. We’re building smarter, more human AI with a diverse community in 100+ countries. 
 
At Welo Data, Limitless AI. Limitless You. isn’t just a slogan—it’s our promise. We build smarter AI through the power of human contribution, offering limitless opportunities for our global community to grow, contribute, and work on their terms.