Senior Full Stack QA Engineer (Freelance)

TL;DR

Senior Full Stack QA Engineer (AI): Take end-to-end ownership of quality across AI-powered distributed systems from AI agents to user interfaces with an accent on handling non-deterministic AI behavior and multi-component interactions. Focus on designing automated tests, debugging issues in complex chains, ruthless prioritization of risks, and shaping QA culture across frontend, backend, and ML teams.

Location: European Union, flexible fully remote work.

Company

We create data that powers leading GenAI models using Experts + Crowd + Tech Platform, working with frontier labs, big tech, and AI startups worldwide.

What you will do

• Take end-to-end ownership of quality: review requirements, shape test strategies, maintain bug reports, track issues, and surface bottlenecks.
• Own quality across the full system including AI agent, orchestration layer, and user/operator interfaces.
• Design and maintain automated tests accounting for non-deterministic AI behavior.
• Debug issues across multi-component distributed systems and identify break points in the chain.
• Prioritize highest-risk areas ruthlessly and decide when to stop testing.
• Use AI tools to write and maintain tests efficiently and shape QA culture without strict rules.

Requirements

• 5+ years of QA experience with strong manual testing foundation
• Experience testing complex, multi-component distributed systems and understanding service interactions
• Practical experience with test automation
• Familiarity with LLMs and AI-first products, understanding non-determinism
• Experience using AI tools (Cursor, Copilot, etc.) in daily workflow
• Strong prioritization skills in high-volume changes and operating in ambiguity

Culture & Benefits

• Freelance collaboration via Ontop platform.
• Flexible, fully remote work schedule.
• Work on innovative AI projects with leading industry customers.
• Dynamic team of experts, friendly community.
• Global distributed remote-first team.