Research Scientist Intern – TikTok Search / Generative AI (LLM) - Global Frontier Tech Recruitment Program - 2027 Start (PhD)

About the role

The TikTok Search team is responsible for delivering a world-class search experience across TikTok’s global ecosystem. Our mission is to connect users with the most relevant and high-quality content through advanced technologies in search ranking, recommendation, and multimodal understanding.

Project Overview, Challenges & Value

This project focuses on building a next-generation generative search system powered by large models to significantly enhance search intelligence and user experience. Key Focus Areas Include:

• Integrating large models with ranking systems to improve personalization and relevance.
• Developing end-to-end generative search models based on multimodal pretraining.
• Exploring large model–driven agent frameworks to better support complex, ambiguous, and multi-turn search scenarios.

Key Challenges

• Personalized ranking: Fully leveraging multimodal signals beyond traditional model capacity.
• Ultra-large-scale retrieval and ranking: Scaling search systems to efficiently handle hundreds of billions of candidates.
• Complex query understanding: Accurately interpreting long, ambiguous, and multi-turn queries to improve user satisfaction.

Qualifications

• Currently pursuing a PhD in Computer Science, Machine Learning, Artificial Intelligence, or related fields.
• Solid foundation in machine learning, deep learning, or information retrieval.
• Familiarity with at least one of the following: LLMs, NLP, search/recommendation, or multimodal learning.
• Proficiency in Python and experience with ML frameworks (e.g., PyTorch, TensorFlow).
• Strong problem-solving skills and willingness to learn in a fast-paced environment.

Preferred Qualifications

• Research experience demonstrated through projects, publications, or open-source contributions.
• Experience with large-scale data, model training, or system implementation.
• Exposure to search, recommendation, or ads systems.
• Experience with multimodal models or generative AI applications.
• Interest in LLMs, agent-based systems, or end-to-end AI applications.
• Previous internship or research experience in industry or labs.