Instacart

Senior Machine Learning Engineer, Search & Recommendations Ranking

Instacart

full-time

Posted on:

Location Type: Remote

Location: CaliforniaColoradoUnited States

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Salary

💰 $173,000 - $219,000 per year

Job Level

About the role

  • Architect the ranking backbone that unifies query understanding, personalization, multi-objective ranking, ads, and merchandising into a single adaptive platform.
  • Design long-horizon objective functions (e.g., incrementality, LTV, habit formation) and build uplift/causal value models that move beyond short-term engagement.
  • Develop production-grade Multi-Task Learning (e.g., shared encoders, MMOE/PLE task heads) to jointly learn relevance, propensity, margin, and churn risk—ensuring calibration, constraints, and explainability.
  • Own the inference layer: goal-aware re-rankers, diversity and quality constraints, safe exploration, and millisecond-class latency optimization.
  • Advance evaluation practices: online experiments, long-horizon cohort metrics, counterfactual evaluations, and attribution pipelines for tracking incremental GTV and retention.
  • Partner across ads, infrastructure, product, and design teams to translate business goals into ranking policies and measurable ROI.
  • Mentor ML engineers to build expertise in ranking, causal inference, and scalable serving systems.

Requirements

  • 5+ years applying ML at scale (3+ years in technical leadership), with a proven track record improving ranking or recommendation systems in production.
  • Demonstrated success in applying multi-objective or constrained optimization to balance relevance, revenue, margin, and user experience; experience with online testing and attribution beyond CTR.
  • Strong coding (Python) and data fluency (SQL/Pandas), with expertise in classic ML techniques (e.g., XGBoost) and deep learning frameworks (TensorFlow/PyTorch).
  • Excellent analytical skills and strong cross-functional communication abilities.
  • Expertise in multi-task learning architectures (e.g., MMOE/PLE, shared encoders), calibration, counterfactual evaluation, uplift/causal modeling, and/or contextual bandits for exploration.
  • Experience building low-latency ranking services, including feature stores, caching, vector + lexical retrieval, re-ranking, and A/B testing infrastructure, with expertise in constraint-aware inference.
  • Hands-on experience with LLMs as feature/recall enhancers (e.g., embeddings, adapter tuning) while maintaining clarity on when the ranker should arbitrate.
Benefits
  • Instacart provides highly market-competitive compensation and benefits in each location where our employees work.
  • Offers may vary based on many factors, such as candidate experience and skills required for the role.
  • This role is eligible for a new hire equity grant as well as annual refresh grants.
Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools
machine learningmulti-objective optimizationconstrained optimizationPythonSQLPandasXGBoostTensorFlowPyTorchmulti-task learning
Soft Skills
analytical skillscross-functional communicationmentoringleadership