LLM Post-training Engineer Intern (Research & Product) - 2026 Summer (BS/MS)
Responsibilities
The Multimedia AI team at TikTok focuses on building, researching, and applying Large Language Models (LLMs) to power our global products. We believe the most impactful problems in AI arise at the intersection of research and real-world deployment-and post-training is where that intersection is sharpest.
We are looking for talented individuals to join us for an internship in 2026. Internships at our Company aim to offer students industry exposure and hands-on experience. Watch your ambitions become reality as your inspiration brings infinite opportunities at our Company.
Internships at Our Company aims to provide students with hands-on experience in developing fundamental skills and exploring potential career paths. A vibrant blend of social events and enriching development workshops will be available for you to explore. Here, you will utilize your knowledge in real-world scenarios while laying a strong foundation for personal and professional growth.
Candidates can apply to a maximum of two positions and will be considered for jobs in the order you apply. The application limit is applicable to Our Company and its affiliates' jobs globally. Applications will be reviewed on a rolling basis - we encourage you to apply early. Please state your availability clearly in your resume (Start date, End date).
Summer Start Dates:
May 11th, 2026
May 18th, 2026
May 26th, 2026
June 8th, 2026
June 22nd, 2026
Responsibilities
- Support the development and optimization of post-training strategies, including instruction tuning, preference tuning (SFT/DPO/PPO), and model alignment.
- Assist in building robust evaluation pipelines to measure model performance, helpfulness, and safety across diverse multimedia product use cases.
- Participate in the research and implementation of cutting-edge methodologies in reward modeling and human preference learning.
- Collaborate with engineering teams to bridge the gap between experimental research and production-ready AI applications (e.g., video understanding, translation, and content classification).
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- Analyze and process large-scale datasets to identify patterns that improve model behavior and alignment quality.
Qualifications
Minimum Qualifications:
- Currently pursuing an Undergraduate or Master's degree in Computer Science, Machine Learning, or a related technical discipline.
- Strong programming skills in Python and experience with deep learning frameworks such as PyTorch or JAX.
- Foundational understanding of Transformer architectures and LLM training principles.
- Demonstrated ability to learn quickly in a fast-paced environment and a strong passion for AI "landing" and product application.
- Able to commit to working for 12 weeks in 2026
Preferred Qualifications:
- Previous experience or research projects involving LLM fine-tuning, RLHF, or synthetic data generation.
- Familiarity with distributed training tools (e.g., DeepSpeed, Megatron-LM).
- Experience or interest in multimodal AI (integrating text with video or audio).
- Proven track record of building and deploying AI projects, either through previous internships, open-source contributions, or academic research.
By submitting an application for this role, you accept and agree to our global applicant privacy policy, which may be accessed here: https://careers.tiktok.com/legal/privacy
Perks and Benefits
Health and Wellness
- Health Insurance
- Dental Insurance
- Vision Insurance
- HSA
- Life Insurance
- Fitness Subsidies
- Short-Term Disability
- Long-Term Disability
- On-Site Gym
- Mental Health Benefits
- Virtual Fitness Classes
Parental Benefits
- Fertility Benefits
- Adoption Assistance Program
- Family Support Resources
Work Flexibility
- Flexible Work Hours
- Hybrid Work Opportunities
Office Life and Perks
- Casual Dress
- Snacks
- Pet-friendly Office
- Happy Hours
- Some Meals Provided
- Company Outings
- On-Site Cafeteria
- Holiday Events
Vacation and Time Off
- Paid Vacation
- Paid Holidays
- Personal/Sick Days
- Leave of Absence
Financial and Retirement
- 401(K) With Company Matching
- Performance Bonus
- Company Equity
Professional Development
- Promote From Within
- Access to Online Courses
- Leadership Training Program
- Associate or Rotational Training Program
- Mentor Program
Diversity and Inclusion
- Diversity, Equity, and Inclusion Program
- Employee Resource Groups (ERG)
Company Videos
Hear directly from employees about what it is like to work at TikTok.