LLM Post-training Engineer Intern (Research & Product) - 2027 Summer

TikTok; San Jose (CA); On-site; USD 52,000 - 72,000; Part time

Benefits offered by this job

Health insurance (day one)

Life insurance

Wellbeing benefits

10 paid holidays per year

Paid sick time

Housing allowance (non-remote)

Job summary

TikTok invites students to join its Multimedia AI team for a campus internship focused on post-training methods, evaluation pipelines, and bridging research with production AI applications across video understanding and content classification.

You will collaborate with engineers on instruction tuning, RLHF, and multimodal experiments while gaining hands-on experience, industry exposure, and opportunities through development workshops and social programs.

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.

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).
• Analyze and process large-scale datasets to identify patterns that improve model behavior and alignment quality.

Skills

Python

PyTorch

JAX

Transformer

LLM training

LLM fine-tuning

RLHF

DeepSpeed

Megatron-LM

Multimodal AI

Education

Pursuing Undergraduate or Master’s in Computer Science, Machine Learning, or related technical discipline

Tools

DeepSpeed

Megatron-LM

Job description

ResponsibilitiesAbout the teamAbout the team TikTok Multimedia AI team 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. Our internship program offers students hands-on experience, industry exposure, and opportunities to apply their knowledge to real-world challenges while building a strong foundation for personal and professional growth.Interns will gain practical experience, explore potential career paths, and participate in social events, learning programs, and development workshops alongside industry professionals.Candidates may apply to a maximum of two positions across Our Company and its affiliates globally. Applications will be considered in the order they are submitted.Applications are reviewed on a rolling basis, so we encourage you to apply early. Please clearly state your availability in your resume, including your start and end dates.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).
• Analyze and process large-scale datasets to identify patterns that improve model behavior and alignment quality.

QualificationsMinimum 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.

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
Job Information
【For Pay Transparency】Compensation Description (Hourly) - Campus Intern
The hourly rate range for this position in the selected city is $45- $45.
Benefits may vary depending on the nature of employment and the country work location. Interns have day one access to health insurance, life insurance, wellbeing benefits and more. Interns also receive 10 paid holidays per year and paid sick time (56 hours if hired in first half of year, 40 if hired in second half of year). Interns who are not working 100% remote may also be eligible for housing allowance.
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:

• Interacting and occasionally having unsupervised contact with internal/external clients and/or colleagues;
• Appropriately handling and managing confidential information including proprietary and trade secret information and access to information technology systems; and
• Exercising sound judgment.

About TikTokTikTok 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