AI Research Scientist Jobs in San Jose, CA

Responsibilities

The TikTok Content Ecology team builds the core algorithm systems for content understanding and ecosystem governance on TikTok. Drawing on platform-scale video content and interaction signals, we apply multimodal large models, natural language processing, computer vision, and recommendation systems to build a content foundation platform supporting search, local services, product infrastructure, PGC, and UGC across TikTok's global business. Our work spans three areas:
1. Unified content understanding. We use multimodal large models for fine-grained semantic parsing of video, building a cross-category, multilingual labeling and event knowledge system that provides reliable foundations for search, recommendation, and safety.
2. Platform-level content governance. We develop high-precision recognition and review models that handle billions of pieces of content daily, addressing low-quality and non-compliant material and supporting compliance requirements for goods and content in areas such as local services.
3. Business growth and user experience. Through trending discovery, inspiration recommendations, and intelligent customer service, we serve creators and users worldwide, improving distribution efficiency, the precision of creative recommendations, and the speed of customer service response.

We work on understanding hundreds of languages and processing multimodal data at hundred-billion scale, in a global business that keeps growing. You will apply NLP, multimodal, and large model technology at real-world scale, seeing your work reach hundreds of millions of users. The Content Ecology Algorithm Team drives TikTok’s AI innovations in LLMs, NLP, Computer Vision (CV), multimodal learning, and recommendation algorithms. We develop cutting-edge AI capabilities that power multiple business lines.

We are seeking exceptional, experienced Research Scientists / Architects in the areas of LLM / Agent Platform. This is a unique role for innovators who are passionate about building the "bones" (scalable infrastructure) of next-generation AI and Agent. You will design and implement novel LLM/Agent frameworks with self-improving capabilities and architect the robust, high-performance infrastructure that brings these LLMs and agents to life at a global scale.

• Architect and build standardized, configurable, and reusable pipelines for the entire lifecycle of models and agents—from data processing and training to deployment, monitoring, and governance.
• Partner with algorithm teams to understand their needs and provide a world-class infrastructure platform that accelerates their research and development cycles.
• Build robust observability and evaluation frameworks to ensure the reproducibility, reliability, and cost-efficiency of AI workloads at scale.
• Design and implement core platform infrastructure, including model/agent registries, feature stores, and high-throughput retrieval/RAG systems.
• Design, build, and optimize advanced Agentic AI systems, focusing on core components like planning, tool use, and memory.

Qualifications

Minimum Qualification(s):
- BS/BA or Master's in Computer Science or related technical field or equivalent technical experience.
- 2+ years of hands-on experience in software engineering, with a focus on machine learning, distributed systems, or AI infrastructure.
- Strong proficiency in integrating AI tools into knowledge discovery and research workflows.
- Familiarity with building robust evaluation frameworks and ensuring experimental reproducibility.
- Expertise in deep learning frameworks and tensor libraries like PyTorch, TensorFlow, JAX/FLAX.
- Solid understanding of machine learning fundamentals and the modern AI stack.
- Excellent communication skills to collaborate across teams.

Preferred Qualification(s):
- PhD in Computer Science or related technical discipline.
- 5+ years of experience as an architect, or technical leadership position.
- Experience with the ML infrastructure ecosystem, including GPU scheduling, model serving (Triton, TensorRT-LLM), vector databases (FAISS, Milvus), and MLOps principles.
- Experience with large-scale model training and inference, including distributed training, KV cache–aware serving, GPU/accelerator optimization, and high-performance networking (e.g., RDMA, NCCL).
- Experience with performance optimization of large model training and inference (e.g., DeepSpeed/ZeRO, vLLM).
- Deep knowledge of agent architectures, including planning, tool use (e.g., LangChain, LlamaIndex), and memory systems.
- Publications in systems and/or machine learning conferences (e.g., NeurIPS, OSDI, SOSP, ASPLOS, MLSys).

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.

TikTok Accommodation

TikTok 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/RA-request

Job Information

【For Pay Transparency】Compensation Description (Annually) The base salary range for this position in the selected city is $162000 - $387600 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.