AI Engineer

Prolific is not just another player in the AI space – we are the architects of the human data infrastructure that reshapes AI development. In a world where foundational AI technologies are increasingly commoditized, the quality and diversity of human-generated data differentiate products and models. The future of AI development relies on a critical, indispensable component: high-quality human data. Prolific provides the world's largest and most trusted source of this data to teams pushing the boundaries of AI technology.

As an AI Engineer, you will build intelligent systems that power the interface between humans and models, shaping how next-generation AI systems are trained, evaluated, and aligned. This is a unique opportunity to solve novel problems and have a foundational impact on the entire AI ecosystem, working with a world-class team and the industry's leading AI labs.

The Role

Responsibilities and expectations are centered on developing production-grade AI systems that enhance how human feedback is collected, validated, and utilized across our platform.

• Architect & Build: Lead the design and implementation of production-grade AI systems that enhance how human feedback is collected, validated, and utilised across our platform.
• Solve Core Challenges: Develop systems for fraud detection, quality assurance, and intelligent participant-to-task matching using techniques like vector search and advanced profile representation.
• Innovate with LLMs: Create and deploy AI agents and systems with immediate product impact—from basic automated data tagging to advanced features like LLM-based evaluation judges, including ideas like synthetic personas.
• Drive Technical Strategy: Provide technical leadership and mentorship on applying AI/LLM techniques, defining best practices for prompt engineering, fine-tuning, and retrieval-augmented generation (RAG).
• Ensure Reliability: Implement and own LLM observability and evaluation systems to ensure AI features are reliable, performant, and continuously improving.
• Collaborate Cross-Functionally: Work with data scientists, platform engineers, and research teams to build cohesive, end-to-end solutions that advance human-AI interaction.

Qualifications

Core Requirements:

• A strong track record of designing, building, and shipping AI-powered features that solve real business problems.
• An inquisitive and experimental mindset with a passion for tackling ambiguous problems without established solutions.
• Deep practical knowledge of the modern AI engineering stack (e.g., RAG, vector databases, prompt engineering, fine-tuning techniques, evaluation frameworks).
• The ability to balance cutting-edge research with production reliability and scalability.
• Deep expertise in one or both of the following areas:

• Software Engineering & Systems Design: Proficiency in Python and building scalable services (e.g., FastAPI, Django). Strong command of system design, infrastructure, and CI/CD; capable of taking a feature from concept to deployment.
• Machine Learning Engineering & Research: Solid ML background with experience in ML frameworks (e.g., PyTorch, TensorFlow, Hugging Face) and understanding of the theory behind models and techniques used.

Bonus Points

• Experience with modern LLM orchestration frameworks (e.g., LangChain, LlamaIndex, DSPy, LangGraph).
• Experience in agentic system design and tool calling (Adk, A2A, MCP, etc.).
• Prior work on human-in-the-loop systems, data annotation platforms, or RLHF.
• Interest or experience in synthetic data, human-in-the-loop systems, or AI alignment.
• Experience building robust monitoring and observability for AI/ML systems in production.

Why Prolific is a great place to work

We’ve built a platform that connects researchers and companies with a global pool of participants to collect high-quality, ethically sourced human data and feedback. This data underpins more accurate, nuanced, and aligned AI systems. We believe the next leap in AI capabilities will come from integrating diverse human perspectives and behaviors into AI development. By providing this crucial human data infrastructure, Prolific positions itself at the forefront of the next wave of AI innovation that reflects the breadth of humanity. Joining us places you at the forefront of AI innovation, with access to our unique human data platform and opportunities for groundbreaking research. We offer a competitive salary, benefits, and remote work within a mission-driven environment.

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