Senior Machine Learning Engineer, E-commerce Recommendation Foundation - USDS

ResponsibilitiesThe E-commerce Recommendation Foundation team is dedicated to building the next-generation recommendation intelligence. We aim to develop a unified Foundation Model that supports multi-business and multi-scenario recommendation systems, covering the full pipeline from retrieval and ranking to re-ranking, and driving a comprehensive upgrade in intelligence and generative capability.We believe the future of recommendation systems goes beyond predicting click-through rates — it lies in understanding the relationship between people and content, and in generating new connections. The team is exploring an event-sequence-driven generative recommendation paradigm, deeply integrating large language models (LLMs), multimodal understanding, reinforcement learning, and system optimization to advance recommendation systems toward general-purpose intelligent agents.We value original exploration and encourage both research thinking and engineering excellence. Every team member is empowered to propose hypotheses and validate ideas in an open environment — your code and papers may help define the next paradigm of recommendation systems. We seek individuals with a general intelligence mindset to join us in redefining the future of recommendation.

Responsibilities

• Build and optimize cross-scenario shared Foundation Models to enable unified modeling and efficient inference. Advance the event-sequence-driven generative recommendation paradigm, integrating multimodal understanding and generative capabilities.- Apply LLM technologies across retrieval, ranking, and re-ranking stages; participate in model training, inference optimization, and system co-design.- Explore the integration of LLMs / VLMs with recommendation systems to develop adaptive and evolving intelligent recommenders.- Research end-to-end generative recommendation and system optimization methods that balance efficiency and user experience.QualificationsMinimum Qualifications- Bachelor's or Master's degree in Computer Science, Machine Learning, or a related field.- 3+ years of experience in machine learning, deep learning, or information retrieval.- Proficiency in Python and familiarity with mainstream deep learning frameworks (e.g., PyTorch).- Strong passion for intelligent recommendation systems and a self-driven research mindset.Preferred Qualifications- PhD degree in Computer Science, Machine Learning, or a related field.- Experience in large-scale recommendation system development or large-model training, with notable technical achievements in a sub-area.- Research experience or publications in LLMs, multimodal learning, reinforcement learning, or generative recommendation.- Familiarity with pre-training and post-training processes for large language models (LLMs) or Foundation Models.About USDSTikTok USDS Joint Venture LLC is dedicated to the safety and security of millions of Americans who create, discover, and connect with what they love on the apps we operate. The Joint Venture has been established in compliance with the Executive Order signed by President Trump on September 25, 2025. Our foundation is a comprehensive data privacy and cybersecurity program we operate under defined safeguards to protect national security and secure U.S. user data, apps and the algorithm. We safeguard the U.S. content ecosystem, holding decision-making authority for trust and safety policies and moderation. USDS Joint Venture helps ensure Americans can continue to express their creativity, discover new hobbies and interests, and build thriving communities and businesses on a global scale.​​On-site presence across teams allows the company to operate with greater speed, alignment, and agility — especially in areas like real-time decision-making, team development, and integrated execution. As such, the company is shifting from a hybrid work model to a fully in-person schedule up to 5 days a week.​Why Join UsInspiring creativity is at the core of TikTok's mission. Our innovative product is built to help people authentically express themselves, discover and connect – and our global, diverse teams make that possible. Together, we create value for our communities, inspire creativity and bring joy - a mission we work towards every day.​We strive to do great things with great people. We lead with curiosity, humility, and a desire to make impact in a rapidly growing tech company. Every challenge is an opportunity to learn and innovate as one team. We're resilient and embrace challenges as they come. By constantly iterating and fostering an "Always Day 1" mindset, we achieve meaningful breakthroughs for ourselves, our company, and our users. When we create and grow together, the possibilities are limitless. Join us.​​Diversity & Inclusion​TikTok is committed to creating an inclusive space where employees are valued for their skills, experiences, and unique perspectives. Our platform connects people from across the globe and so does our workplace. At TikTok, our mission is to inspire creativity and bring joy. To achieve that goal, we are committed to celebrating our diverse voices and to creating an environment that reflects the many communities we reach. We are passionate about this and hope you are too.​USDS Reasonable AccommodationUSDS is committed to providing reasonable accommodations in our recruitment processes for candidates with disabilities, pregnancy, sincerely held religious beliefs or other reasons protected by applicable laws. If you need assistance or a reasonable accommodation, please reach out to us at https://tinyurl.com/USDS-RA​Job Information【For Pay Transparency】Compensation Description (Annually)The base salary range for this position in the selected city is $198360 - $416100 annually.​Compensation may vary outside of this range depending on a number of factors, including a candidate’s qualifications, skills, competencies and experience, and location. Base pay is one part of the Total Package that is provided to compensate and recognize employees for their work, and this role may be eligible for additional discretionary bonuses/incentives, and restricted stock units.​Benefits may vary depending on the nature of employment and the country work location. Employees have day one access to medical, dental, and vision insurance, a 401(k) savings plan with company match, paid parental leave, short-term and long-term disability coverage, life insurance, wellbeing benefits, among others. Employees also receive 10 paid holidays per year, 10 paid sick days per year and 17 days of Paid Personal Time (prorated upon hire with increasing accruals by tenure).​The Company reserves the right to modify or change these benefits programs at any time, with or without notice.​For Los Angeles County (unincorporated) Candidates:​Qualified applicants with arrest or conviction records will be considered for employment in accordance with all federal, state, and local laws including the Los Angeles County Fair Chance Ordinance for Employers and the California Fair Chance Act. Our company believes that criminal history may have a direct, adverse and negative relationship on the following job duties, potentially resulting in the withdrawal of the conditional offer of employment:​1. Interacting and occasionally having unsupervised contact with internal/external clients and/or colleagues;​2. Appropriately handling and managing confidential information including proprietary and trade secret information and access to information technology systems; and​3. Exercising sound judgment.​