Senior Machine Learning Engineer, Recommendations

Lyft

At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. The Rider team is the heartbeat of Lyft business. Every feature you build translates to a better experience for millions of riders globally. The Rider New Product team is the engine of innovation for Lyft's business. The Rider New Product science team’s mission is to rigorously quantify the value of innovation by applying advanced causal inference to unlock Lyft’s next generation of growth. You will have the autonomy of a startup lead with the data scale of a global tech giant. This is a high-impact, highly technical role within a core business line. The ideal candidate brings strong applied causal inference intuition, hands-on experience with advanced measurement techniques, and the ability to write clean, efficient production code. You will play a critical role in shaping the future of the Lyft rideshare experience by rigorously measuring the true incremental impact of new product features, shaping critical business decisions, and bridging the gap between cutting-edge applied science research and production-scale product impact. RESPONSIBILITIES * Own complex, open-ended incrementality measurement problems. Translate ambiguous product launches into concrete causal frameworks and experimental designs. * Lead high-impact Causal Inference initiatives. Drive innovation by introducing advanced measurement techniques to quantify the incremental impact of new rider features. * Partner deeply with Product, Engineering, and Finance. Define the technical vision for how Lyft evaluates innovation, ensuring that we move beyond simple correlations to understand the long-term drivers of rider behavior and value. * Design and build production-grade measurement systems. Develop and deploy robust causal models pipelines that balance high scientific rigor with the practical constraints. * Establish robust evaluation frameworks. Ensure that the "engine of innovation" is steering the business toward sustainable, incremental growth. * Build reusable science infrastructure. Create internal libraries and best practices for causal discovery and automated measurement. * Mentor and guide junior/mid-level scientists. Serve as a technical advisor on experimental design, statistical modeling, and fostering a culture of scientific excellence. EXPERIENCE: * Advanced Quantitative Background: Master’s or PhD in Economics, Statistics, Applied Math, Computer Science or equivalent high-impact industry experience. * 3+ Years of Applied Experience: Proven track record in applied science or data science, with a focus on deploying causal models that drive measurable business outcomes. * Deep product intuition and hands-on experience with causal methods * Strong proficiency in Python and SQL. * Experienced in defining and executing sophisticated evaluation strategies, including advanced experiment design and counterfactual analysis to isolate incrementality. * Proven ability to align cross-functional partners, influence technical architecture, and challenge scientific assumptions to guide high-level product strategy. * Excellent ability to articulate complex causal concepts, trade-offs between rigor and speed, and scientific findings to both technical peers and executive stakeholders. * Preferred Qualifications * Demonstrated ability to own high-stakes, open-ended problem spaces, translating vague business questions into rigorous scientific roadmaps. * Experience in mentoring other scientists, elevating the bar for technical quality, and establishing best practices for modeling and scientific reasoning. BENEFITS: * Great medical, dental, and vision insurance options with additional programs available when enrolled * Mental health benefits * Family building benefits * Child care and pet benefits * 401(k) plan to help save for your future * In addition to 12 observed holidays, salaried team members have discretionary paid time off, hourly team members have 15 days paid time off * 18 weeks of paid parental leave. Biological, adoptive, and foster parents are all eligible * Subsidized commuter benefits * Lyft Pink - Lyft team members get an exclusive opportunity to test new benefits of our Ridership Program Lyft is an equal opportunity employer committed to an inclusive workplace that fosters belonging. All qualified applicants will receive consideration for employment without regards to race, color, religion, sex, sexual orientation, gender identity, national origin, disability status, protected veteran status, age, genetic information, or any other basis prohibited by law. We also consider qualified applicants with criminal histories consistent with applicable federal, state and local law. Lyft highly values having employees working in-office to foster a collaborative work environment and company culture. This role will be in-office on a hybrid schedule — Team Members will be expected to work in the office 3 days per week on Mondays, Wednesdays, and Thursdays. Lyft considers working in the office at least 3 days per week to be an essential function of this hybrid role. Your recruiter can share more information about the various in-office perks Lyft offers. Additionally, hybrid roles have the flexibility to work from anywhere for up to 4 weeks per year. #Hybrid The expected base pay range for this position in the San Francisco area is $148,000 - $185,000, not inclusive of potential equity offering, bonus or benefits. Salary ranges are dependent on a variety of factors, including qualifications, experience and geographic location. Your recruiter can share more information about the salary range specific to your working location and other factors during the hiring process.

Lyft

At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive.  Lyft connects people to transportation to change the way we live and get around our communities. We are looking for product managers who bring exceptional creative, strategic, and analytical skills to drive forward a best in class product. Product management at Lyft leads the integration of engineering, data science, and design to achieve the company’s vision for reinventing transportation. We are looking for entrepreneurial and passionate Product Managers to innovate and execute across a rapidly growing, fast paced company and industry. The Rider team is responsible for the Lyft consumer app that you know and love (we hope!), and spans the entire consumer journey across the request and purchase flows, search, pickups and drop offs, the post-match experience, and the in-trip experience. We're hiring a Product Manager to lead our Golden Path strategy, owning the core ride request flows. The ideal candidate combines deep user empathy with strong analytical skills, has a proven track record driving core consumer product strategy, and excels at cross-functional collaboration to deliver experiences that embody Lyft's mission. RESPONSIBILITIES: * Drive strategic alignment by analyzing Lyft's competitive landscape and market position to define an ambitious product vision that motivates teams and leadership. Set team goals and success metrics that directly support Lyft's mission while maximizing business impact through rigorous data analysis, competitive intelligence, and user research insights. * Lead through uncharted product territory by analyzing fragmented data and emerging patterns to define strategic direction in ambiguous problem spaces, transforming incomplete insights and conflicting stakeholder priorities into clear product vision, actionable frameworks, and executable roadmaps. * Deliver on this vision by setting your team's goals, success metrics and roadmap and collaborating extremely effectively across the company. * Build a product roadmap to achieve your goals and lead a core team of engineers, designers, data scientists, and marketers to execute on it. * Deeply understand the needs and motivations of your customers.  * Completely own your team’s products – existing or new – from ideation, through development, launch, growth, and maintenance. * Clearly communicate roadmaps, priorities, experiments, and decisions across a wide spectrum of audiences from partner teams to executive levels. EXPERIENCE: * 4+ years in product management, product design or equivalent consultant experience with significant time spent leading consumer facing products.  * Natural leadership and ability to make things happen. You manage project ambiguity, complexity, and interdependencies in an organized and structured way, and you are able to define and analyze metrics that inform the success of your products. * Excellent judgment and thoughtfulness about the dynamics of the product ecosystem. * Strong communication skills and intuition for communication strategy at every level -- within teams, within the company, to users, and other audiences. * Ability to conceptualize, prioritize and lead multiple projects for stakeholders. * Detail oriented with superior organizational skills -- balancing multiple projects, deadlines, and requests should be second nature to you. * Background in membership, subscription, or loyalty program development in consumer-facing products or services preferred BENEFITS: * Great medical, dental, and vision insurance options with additional programs available when enrolled * Mental health benefits * Family building benefits * Child care and pet benefits * 401(k) plan with company match to help save for your future * In addition to 12 observed holidays, salaried team members have discretionary paid time off, hourly team members have 15 days paid time off * 18 weeks of paid parental leave. Biological, adoptive, and foster parents are all eligible * Subsidized commuter benefits * Monthly Lyft credits and complimentary Lyft Pink membership Lyft is an equal opportunity employer committed to an inclusive workplace that fosters belonging. All qualified applicants will receive consideration for employment without regards to race, color, religion, sex, sexual orientation, gender identity, national origin, disability status, protected veteran status, age, genetic information, or any other basis prohibited by law. We also consider qualified applicants with criminal histories consistent with applicable federal, state and local law. Lyft highly values having employees working in-office to foster a collaborative work environment and company culture. This role will be in-office on a hybrid schedule — Team Members will be expected to work in the office 3 days per week on Mondays, Wednesdays, and Thursdays. Lyft considers working in the office at least 3 days per week to be an essential function of this hybrid role. Your recruiter can share more information about the various in-office perks Lyft offers. Additionally, hybrid roles have the flexibility to work from anywhere for up to 4 weeks per year. #Hybrid The expected base pay range for this position in the San Francisco area is $148,000 - $185,000, not inclusive of potential equity offering, bonus or benefits. Salary ranges are dependent on a variety of factors, including qualifications, experience and geographic location. Your recruiter can share more information about the salary range specific to your working location and other factors during the hiring process.

Instacart

We're transforming the grocery industry At Instacart, we invite the world to share love through food because we believe everyone should have access to the food they love and more time to enjoy it together. Where others see a simple need for grocery delivery, we see exciting complexity and endless opportunity to serve the varied needs of our community. We work to deliver an essential service that customers rely on to get their groceries and household goods, while also offering safe and flexible earnings opportunities to Instacart Personal Shoppers. Instacart has become a lifeline for millions of people, and we’re building the team to help push our shopping cart forward. If you’re ready to do the best work of your life, come join our table. Instacart is a Flex First team There’s no one-size fits all approach to how we do our best work. Our employees have the flexibility to choose where they do their best work—whether it’s from home, an office, or your favorite coffee shop—while staying connected and building community through regular in-person events. Learn more about our flexible approach to where we work. Overview The Search & Personalization ML team is Instacart’s engine for state-of-the-art multi-task, multi-objective ranking—unifying search, discovery, recommendation, ads, and merchandising into a single value-aware platform. Partnering with world-class engineers, scientists, and PMs, we build the ranking backbone that powers every pixel of the shopping journey, optimizing not just for clicks, but for incremental GTV, basket lift, and retention over the long run. What We’re Building * Foundational Ranking Backbone Models: Multi-task/multi-objective models (shared encoders + task heads) that jointly learn relevance, conversion, margin contribution, churn risk, and ad quality, enabling consistent decisions across search and recommendations. * Value-Aware Optimization: Uplift and long-horizon value models that steer decisions toward incrementality and LTV, with calibrated constraints on quality, diversity, fairness, and spend pacing—plus guardrails for safe exploration. * LLM-Enhanced Retrieval & Features: Using LLMs to enrich query and item semantics for long-tail recall, generate features for cold-starts, and feed the ranker with reasoning-rich context, while remaining the source of truth for final ordering. Our commitment to AI innovation is reflected in our recent publications and research contributions to the field.   About the Job * Architect the ranking backbone that unifies query understanding, personalization, multi-objective ranking, ads, and merchandising into a single adaptive platform. * Design and build a search autosuggest system optimized for personalization and value-based relevance. * 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.   About You Minimum Qualifications * 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. Preferred Qualifications * 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. Instacart provides highly market-competitive compensation and benefits in each location where our employees work. This role is remote and the base pay range for a successful candidate is dependent on their permanent work location. Please review our Flex First remote work policy here. Offers may vary based on many factors, such as candidate experience and skills required for the role. Additionally, this role is eligible for a new hire equity grant as well as annual refresh grants. Please read more about our benefits offerings here. For US based candidates, the base pay ranges for a successful candidate are listed below. CA, NY, CT, NJ $207,000—$253,500 USD WA $198,000—$243,000 USD OR, DE, ME, MA, MD, NH, RI, VT, DC, PA, VA, CO, TX, IL, HI $190,000—$233,000 USD All other states $173,000—$212,000 USD