Machine Learning Engineer, Search - USDS

Responsibilities

About the Team

The Search team is responsible for the machine learning algorithm for TikTok's rapidly growing video search, ecommerce search, local service search and AI search business. We use state-of-the-art large-scale machine learning technology, cutting-edge NLP, CV and multi-modal technology, and generative models (LLM, VLM) to build the industry's top-class search engines to provide the best search experience, for more than 1 billion monthly TikTok users around the world.

Responsibilities

• Improve the basic search quality and user experience: Optimize query analysis and text relevance matching. Understand video content and implement multi-modal matching. Improve users' perception of product authority, and deeply participate in the design and implementation of core search products. Comprehensively improve the end-to-end user experience.
• Design and implement the end-to-end ranking system (recall, first stage ranking, final stage ranking and mixed row): Use massive behavioral data to deeply model users' personalized interests.
• Promote the development of the ecosystem: From the perspective of technology and businesses, solve challenging problems such as supply and demand matching, business cold start, and sustainable business growth, etc. Think, analyze and adjust the evolution of the system to achieve long-term and sustainable growth of GMV
• Innovation with Generative Recommendation Systems: Drive the integration of generative recommendation approaches, leveraging LLMs to directly generate personalized content recommendations, moving beyond traditional ranking-based methods. This includes exploring frameworks like GenRec, which utilize LLMs to interpret user contexts and generate relevant recommendations.
• Cross-functional Collaboration: Work closely with product managers, data scientists, infrastructure engineers, operation teams to enable search personalization strategies with overall product goals.

Qualifications

Minimum Qualifications

• Bachelor's or advanced degree in Computer Science, Machine Learning, or a related field.
• Proficient in machine learning frameworks (e.g., TensorFlow, PyTorch), programming languages (e.g., Python, Java, C++), and deep understanding of data structures and algorithms.
• 2+ years in developing large-scale search or recommendation systems (feed, search, advertisement, etc). Familiarity with generative recommendation frameworks and their application in large-scale systems is highly desirable.

Preferred Qualifications

• Prior experience in search, recommendation, or advertisement algorithms.
• Publication records in journals or conferences.

About USDS

TikTok 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 Us

Inspiring 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 environmen