Senior/Tech Lead QA with AI experience (Part-time)

N-iX is looking for a Senior/Tech Lead QA Engineer with AI experience to join our team. We're looking for a hands-on  Senior/Tech Lead QA Engineer who can cover the full testing spectrum: UI, API, and AI/ML output validation. You'll be joining a project building an AI-powered document analysis platform from the ground up. The system combines a CMS backend, modern UI, and a RAG-based AI layer used for intelligent document processing and analysis. Responsibilities: - Design and execute test cases for REST APIs, covering functional correctness, edge cases, error handling, authentication, and data integrity - Follow a phased QA approach — begin with CMS and backend testing to establish a reliable baseline of expected system behavior, then apply those insights to validate AI agent outputs effectively - Perform UI testing across core user journeys, validating layout, behavior, and integration with backend services - Transition into AI output validation once the deterministic layers are stable — using your knowledge of business rules to identify inconsistencies, hallucinations, or degraded outputs in agent responses - Document and maintain test cases, test plans, and bug reports in a structured and traceable way - Participate in requirement reviews and technical discussions to identify testability gaps early - Collaborate with the Lead Big Data/AI Engineer and AI team to understand RAG pipeline behavior, document ingestion flows, and output quality expectations - Contribute to building reusable test assets and QA processes as the project scales Requirements: - 5+ years of experience in manual QA, with exposure to frontend, backend, and AI testing - Solid experience with API testing using tools such as Postman, REST Client, or similar - Nice to have experience with test automation for web applications and/or APIs using tools or frameworks such as Playwright, Cypress, Selenium, pytest, or similar. - Ability to determine which test scenarios are suitable for automation versus manual validation. - Experience testing web UIs and understanding of cross-browser/cross-environment considerations - Ability to read and interpret API documentation, data schemas, and system architecture descriptions - Hands-on experience working on projects that included AI, ML, or NLP components — particularly validating outputs that are probabilistic or context-dependent - Familiarity with the concept of RAG (Retrieval-Augmented Generation) or LLM-based systems - Strong analytical thinking — especially the ability to assess whether an AI response is contextually correct, not just technically non-null - Good understanding of test documentation practices: test plans, test cases, bug reports, traceability - Experience working in Agile/Scrum teams - Upper-Intermediate English or higher — you'll be communicating directly with the client and cross-functional team members - Familiarity with Palantir Foundry is a strong plus We offer*: - Flexible working format - remote, office-based or flexible - A competitive salary and good compensation package - Personalized career growth - Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more) - Active tech communities with regular knowledge sharing - Education reimbursement - Memorable anniversary presents - Corporate events and team buildings - Other location-specific benefits *not applicable for freelancers