ML Engineer, Multimodal Safety & Content Moderation

TikTok Inc.; San Jose (CA); On-site; USD 162,000 - 388,000; Full time

Job summary

TikTok Inc. in San Jose is seeking researchers and engineers to build next-generation Trust & Safety systems across TikTok, Lemon8 and other platforms. You will advance multimodal understanding and risk detection using LLMs, AI agents, and scalable pipelines.

You will train and apply LLMs/MLLMs, explore post-training techniques, and work with cross‑functional teams to deliver robust moderation solutions. The role emphasizes production-ready models and ongoing innovation.

Qualifications

• Bachelor degree or above in Computer Science, Software Engineering, Artificial Intelligence, Mathematics, or related fields
• Strong understanding of machine learning and deep learning, with familiarity with Transformer architectures, LLMs, and MLLMs
• Hands-on experience in Python, PyTorch, distributed training, and large-scale data processing, with solid algorithmic and engineering capabilities
• Proven ability to solve complex problems and collaborate effectively in cross-functional teams, with a track record of driving projects to high-quality execution

Responsibilities

• Develop content safety algorithms for TikTok, Lemon8, and short-form drama platforms, covering multimodal understanding and risk detection across video, text, image, and audio
• Leverage machine learning, deep learning, and large model technologies to improve content moderation pipelines, enhance operational efficiency, and ensure model robustness and production stability
• Own the training and application of LLMs and MLLMs for content safety use cases, including post-training techniques such as SFT, RLHF, DPO, and safety alignment
• Drive the exploration and productionization of emerging capabilities such as AI Agents, multimodal reasoning, and video understanding to build next-generation intelligent moderation systems

Skills

ML foundations

Python

PyTorch

Cross-functional collaboration

Education

Bachelors or above in CS/AI/math

Job description

TikTok Inc. in San Jose is seeking researchers and engineers to build next-generation Trust & Safety systems across TikTok, Lemon8 and other platforms. You will advance multimodal understanding and risk detection using LLMs, AI agents, and scalable pipelines.

You will train and apply LLMs/MLLMs, explore post-training techniques, and work with cross‑functional teams to deliver robust moderation solutions. The role emphasizes production-ready models and ongoing innovation.