Principal Engineer - AI/ML

About the Role

Key Responsibilities

• Lead the architecture and development of Quizlet's Learning Knowledge Graph, using unsupervised representation learning and entity linking techniques to model relationships between learners and study concepts.
• Design and deploy next-generation semantic search and retrieval-augmented generation (RAG) systems to improve content discovery relevance and quality.
• Drive the strategy and execution of identifying and developing learning foundation models, guiding the transition from external LLMs to Quizlet-specific multimodal models for personalized AI tutoring.
• Establish an industry-defining benchmark and evaluation framework to measure pedagogical effectiveness and guide future model development.
• Build and scale robust, state-of-the-art MLOps pipelines to support rapid experimentation and deployment of AI features.
• Mentor and guide other engineers, setting technical standards and fostering a culture of innovation and research.

Requirements

• 8+ years of experience applying AI research to build real-world products in industrial and academic environments.
• A Ph.D. in Computer Science, Machine Learning, Natural Language Processing, or a related field.
• Proven track record of leading high-impact projects and publishing in top-tier ML/NLP conferences (e.g., NeurIPS, ICML, ACL, EMNLP).
• Deep technical expertise in pre-training and fine-tuning large language models, retrieval-augmented generation, and unsupervised representation learning.
• Extensive experience building and deploying scalable, high-performance ML systems serving millions of users.
• Strong foundation in software engineering principles and proficiency in languages like Python and C++, and libraries like PyTorch or TensorFlow.

Nice to Have

• A background in creating sophisticated LLM agents that can perform multi-step reasoning and research.
• Experience in advanced NLP tasks such as entity linking, coreference resolution, and question answering.
• A passion for open-source projects and a history of contributing to the AI community.

Benefits & Perks

• Market competitive total compensation, including a starting base salary of $245,000 - $315,000 depending on location and experience, plus stock options.
• Collaborate with your manager and team to create a healthy work-life balance.
• 20 vacation days.
• Competitive health, dental, and vision insurance (100% employee and 75% dependent PPO, Dental, VSP).
• Employer-sponsored 401k plan with company match.
• Access to LinkedIn Learning and other professional growth resources.
• Paid Family Leave, FSA, HSA, Commuter benefits, Wellness benefits.
• 40 hours of annual paid time off for volunteer programs.