LLM Post-training Engineer Intern (Research & Product) - 2027 Summer San Jose Undergraduate/Mas[...]

TikTok; San Jose (CA); On-site; USD 51,000 - 73,000; Part time

Benefits offered by this job

Health insurance

Paid holidays

Paid sick time

Housing allowance

Job summary

TikTok in San Jose offers an AI internship focused on post-training methods for LLMs and multimodal AI. You will work with the Multimedia AI team to explore instruction tuning, evaluation pipelines, and alignment strategies while collaborating with engineers to bring research into production-ready applications.

The role suits students pursuing CS/ML degrees, with strong Python skills and experience in PyTorch or JAX. A dynamic, learning-oriented environment awaits.

Qualifications

• Pursuing an Undergraduate or Master’s degree in CS, ML, or related field.
• Strong Python programming and DL framework experience (PyTorch/JAX).
• Foundational understanding of Transformer architectures and LLM training.
• Ability to learn quickly in a fast-paced environment and interest in AI deployment/applications.
• Experience with LLM fine-tuning, RLHF, or synthetic data.
• Familiarity with distributed training tools (DeepSpeed, Megatron-LM).
• Interest in multimodal AI (text with video/audio).
• Record of AI project work or internships.

Responsibilities

• Support post-training strategies (instruction tuning, SFT/DPO/PPO, model alignment).
• Assist in building evaluation pipelines for model performance, helpfulness and safety across multimedia use cases.
• Research and implement reward modeling and human preference learning techniques.
• Collaborate with engineering to bridge research and production-ready AI apps (video understanding, translation, classification).
• Analyze large-scale datasets to identify patterns improving model behavior and alignment.

Skills

Python

PyTorch

Transformer architectures

LLM training principles

Adaptability

Education

Undergraduate or Master’s in CS/ML

Tools

DeepSpeed

Megatron-LM

Distributed training

Job description

Location:

San Jose

Employment Type:

Intern

Job Code:

A08601A

Responsibilities

About the teamThe 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. 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.

• 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.

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.

• 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.

Job Information

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:

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.

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