Research Scientist - LLM Applications for International E-commerce Scenarios - Global Frontier Tech Recruitment Program - 2027 Start (PhD)

About TikTok TikTok is the leading destination for short-form mobile video. At TikTok, our mission is to inspire creativity and bring joy. TikTok's global headquarters are in Los Angeles and Singapore, and we also have offices in New York City, London, Dublin, Paris, Berlin, Dubai, Jakarta, Seoul, and Tokyo.​ 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 environment that reflects the many communities we reach. We are passionate about this and hope you are too. Responsibilities We are looking for talented individuals to join our team in 2027. As a graduate, you will get opportunities to pursue bold ideas, tackle complex challenges, and unlock limitless growth. Launch your career where inspiration is infinite at our Company.Successful candidates must be able to commit to an onboarding date by end of year 2027. Please state your availability and graduation date clearly in your resume.Team Introduction: The Data-Global E-Commerce team serves as the core technological engine for ByteDance's Global E-commerce. We specialize in pioneering algorithmic and big data innovations within the E-commerce sector, driven by our mission: "To make a beautiful life readily accessible and to help unique, high-quality products reach a global market." Our work involves: Developing advanced recommendation and search algorithms to help users efficiently discover products that match their interests. Leveraging cutting-edge risk control and platform governance technologies to ensure a secure shopping environment for all users. Constructing a comprehensive product knowledge graph and intelligent customer service systems to elevate the intelligence of every stage of the transaction process. Integrating machine learning with operations research algorithms to continuously optimize supply chain and logistics efficiency, thereby reducing operational costs. Providing merchants with intelligent business tools that empower them to enhance their operational efficiency and customer service experience. By joining us, you will collaborate with world-class product and technology teams, leveraging ByteDance's extensive traffic and data ecosystem to drive the deep integration and application of technology across various e-commerce scenarios.Topic Content: In today’s global e-commerce landscape, intelligent systems must operate across increasingly complex and dynamic business environments. Yet existing approaches still face limitations in long-horizon forecasting, cross-modal understanding, and holistic decision-making.This initiative is focused on building a next-generation foundational large model purpose-built for global e-commerce applications. The model will integrate key business dimensions—such as users, products, content, logistics, and inventory—into a unified representation to support deep, context-aware intelligence at scale.Building on this foundation, we are developing a modular, agent-driven architecture that enables advanced capabilities including task planning, tool use, multi-turn reasoning, and real-world environment interaction. Topic Challenges: 1. Heterogeneous fusion and alignment: Unified modeling of user behavior sequences, product sales time-series signals, and multimodal product content to achieve deep semantic alignment across high-dimensional temporal data and multimodal representations. 2. Synergy between recommendation LLMs and world models: Reformulating the recommendation problem as a generative task of producing ranked item lists for users, and leveraging large model technologies to enable end-to-end recommendation modeling. 3. Tokenizer of recommendation items: Designing scalable tokenization mechanisms to encode billions of items into multimodal and semantically rich representations, supporting training and generation tasks. This includes pretraining over tens of terabytes of user behavior tokens, improving scaling law performance through optimized model architectures and training strategies, and reframing diverse recommendation tasks as post-training objectives. Recommendation modeling is further enhanced using RLVR-style approaches to maximize GMV and user experience. In addition, training and inference are co-optimized, with high-performance recommendation systems built on large-model inference frameworks such as SGLang. 4. Multimodal large models for e-commerce: Developing multilingual, multimodal large models tailored for e-commerce, achieving state-of-the-art (SOTA) performance across core e-commerce scenarios. Building on this foundation, we establish an e-commerce agent backbone to enable scalable deployment of agent applications across diverse use cases. 5. Agent evaluation, safety, and compliance: Establishing evaluation metrics and benchmarks aligned with real-world business scenarios to ensure the robustness, safety, and complianc…