Machine Learning Engineer, Personalization and Recommendations
San Francisco, CA - USA
Job Summary
About the Team:
The Personalization & Recommendations team at Quizlet is building personalized learning experiences that help millions of learners study more effectively. We are looking for Machine Learning Engineers ranging from the Senior to Staff as well as Sr. Staff levels (note: leveling decisions made through the interview process).
Youll bring strong expertise in modern recommender systems from deep learningbased retrieval and embeddings to multi-stage ranking and evaluation and contribute to the evolution of Quizlets personalization capabilities. Youll work at the intersection of machine learning product and scalable systems ensuring our recommendations are performant responsible and aligned with learner outcomes privacy and fairness.
Were happy to share that this is an onsite position. To help foster team collaboration we require that employees be in the office a minimum of three days per week: Monday Wednesday and Thursday and as needed by your manager or the company. We believe this work environment enhances efficiency fosters collaboration and supports growth for both employees and the organization.
In this role you will:
- Design and implement personalization models across candidate retrieval ranking and post-ranking layers leveraging user embeddings contextual signals and content features.
- Develop scalable retrieval and serving systems using architectures such as Two-Tower models deep ranking networks and ANN-based vector search for real-time personalization.
- Build and maintain model training evaluation and deployment pipelines ensuring reliability training-serving consistency observability and robust monitoring.
- Partner with Product and Data Science to translate learner objectives such as engagement retention and mastery into measurable modeling goals and experiment designs.
- Advance evaluation methodologies contributing to offline metric design such as NDCG CTR AUC and calibration and supporting rigorous A/B testing to measure learner and business impact.
- Collaborate with platform and infrastructure teams to optimize distributed training inference latency and serving cost in production environments.
- Stay informed on industry and research trends evaluating opportunities to meaningfully apply them within Quizlets ecosystem.
- Mentor engineers supporting technical growth experimentation rigor and responsible ML practices.
- Champion collaboration inclusion curiosity and data-driven problem solving contributing to a healthy and productive team culture.
- Depending on level contribute to broader technical strategy guide architectural decisions and influence personalization direction across teams and product surfaces.
What you bring to the table:
- Minimum 5 years of experience in applied machine learning or ML-heavy software engineering with a strong focus on personalization ranking or recommendation systems.
- Demonstrated impact improving key metrics such as CTR retention engagement or other learner-facing outcomes through recommender or search systems in production.
- Strong hands-on skills in Python and PyTorch with expertise in data and feature engineering distributed training and inference on GPUs and familiarity with modern MLOps practices including model registries feature stores monitoring and drift detection.
- Deep understanding of retrieval and ranking architectures such as Two-Tower models deep cross networks Transformers MMoE or similar approaches and the ability to apply them to real-world problems.
- Experience with large-scale embedding models and vector search systems including FAISS ScaNN or similar technologies.
- Proficiency in experiment design and evaluation connecting offline metrics such as AUC NDCG and calibration with online A/B test outcomes to drive product decisions.
- Clear effective communication with the ability to collaborate well with product managers data scientists engineers and cross-functional partners.
- A growth and mentorship mindset helping elevate team quality in modeling experimentation and reliability.
- Commitment to responsible and inclusive personalization ensuring our systems respect learner privacy fairness and diverse goals.
Additional strengths for Senior Staff candidates:
- Experience shaping technical strategy across teams or disciplines balancing long-term architectural vision with near-term product and business priorities.
- Demonstrated leadership through influence including aligning stakeholders guiding teams through ambiguity and driving accountability for outcomes.
- Ability to communicate complex technical trade-offs clearly to senior leadership and cross-functional audiences.
- Experience mentoring senior engineers or applied scientists and helping raise the technical bar across an organization.
- Proven ability to lead large ambiguous initiatives and influence platform product and modeling direction at scale.
Bonus points if you have:
- Publications or open-source contributions in RecSys search or ranking.
- Familiarity with reinforcement learning for recommendations or contextual bandits.
- Experience with hybrid RecSys systems blending collaborative filtering content understanding and LLM-based reasoning.
- Prior work in consumer or EdTech applications with personalization at scale.
Compensation Benefits & Perks:
- Quizlet is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Salary transparency helps to mitigate unfair hiring practices when it comes to discrimination and pay gaps. Total compensation for this role is market competitive including a base salary of $175000 to $330000 depending on location level (Senior Staff or Senior Staff) and experience as well as company stock options
- Collaborate with your manager and team to create a healthy work-life balance
- 20 vacation days that we expect you to take!
- Competitive health dental and vision insurance (100% employee and 75% dependent PPO Dental VSP Choice)
- Employer-sponsored 401k plan with company match
- Access to LinkedIn Learning and other resources to support professional growth
- Paid Family Leave FSA HSA Commuter benefits and Wellness benefits
- 40 hours of annual paid time off to participate in volunteer programs of choice
Required Experience:
IC
About Company
Quizlet makes simple learning tools that let you study anything. Start learning today with flashcards, games and learning tools — all for free.