Machine Learning Engineer, TikTok Risk & Integrity - USDS

The USDS Platform and Community Integrity (PaCI) team is the architectural backbone of Tik Tok's Risk & Integrity in the US. We drive end-to-end integrity for Tik Tok and its expanding ecosystem, including Lemon8 and emerging affiliate platforms, by leveraging localized US data and state-of-the-art AI/LLM capabilities.

Our mission is to deliver AI-driven algorithmic solutions that detect and neutralize systemic threats across critical domains: from Account Integrity, Feed, and Social to Tik Tok Live, Local Services, and User Growth. We architect the core ML infrastructure and risk intelligence that protect our billion-user ecosystem from adversarial threats.

• Global Ecosystem Governance:
  Lead the algorithmic architecture and governance for Tik Tok US across key domains, including account integrity, incentive abuse, content safety, and financial risk, ensuring a fair and secure ecosystem for a billion-user community.
• Universal Representation Modeling:
  Build high-precision, risk representation models leveraging massive heterogeneous data (video, live streams, audio, behavior sequences, and social graphs) to enable cross-scenario risk perception.
• Dynamic Adversarial Defense:
  Research and counter global adversarial threats (e.g., large-scale automated attacks, AIGC harmful content). Architect self-evolving defense systems that maintain robustness and resilience against rapid tactic shifts and data drift.
• Intelligent Decision-making:
  Drive the integration of Generative AI and Multimodal technologies into the risk lifecycle. Leverage LLMs and deep learning models to solve complex adjudication and interpretability challenges, balancing precision with automated, large-scale enforcement.

• Bachelor's degree or higher in Computer Science, Mathematics, Statistics, or a related field.
• Solid foundation in Machine Learning; proficient in applying Transformer and GNN architectures to solve large-scale integrity challenges with social graph and behavior sequence data. Experience designing model evaluation systems that balance technical performance with product goals.
• Strong engineering and coding skills. Proficient in at least one language among Python, C++, or Go; familiar with distributed computing (e.g., Spark, Flink) and deep learning frameworks (e.g., PyTorch).
• A passion for building world‑class risk infrastructure and the ability to communicate effectively in a global, cross‑cultural environment.

• Agentic AI
  
  Experience:
  
  Hands‑on experience building LLM-based Agents capable of task planning, tool‑use, or closed‑loop autonomous decision‑making.
• LLM Security & Alignment:
  Experience in LLM Post‑training or Fine‑tuning (e.g., SFT, RLVR, RLHF) to optimize models for specific risk domains like fraud intent recognition or malicious redirection.
• Multimodal Expertise:
  Proven track record in video understanding or multimodal representation; ability to integrate visual, audio, and textual features to solve complex behavioral modeling challenges.
• Industry Vision:
  Experience in Integrity, Anti‑Abuse, Safety, or Trustworthy AI at a large‑scale internet platform.

USDS 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

Compensation Description (Annually)

The base salary range for this position in the selected city is $129,960 - $246,240 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…