LLM Post-training Engineer Graduate; Research & Product

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@2026 Tik Tok

Technology

Location:

San Jose

Employment Type:

Regular

Job Code:

A212612

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Responsibilities

About the team

The Multimedia AI team at Tik Tok 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 our team. As a graduate, you will get opportunities to pursue bold ideas, tackle complex challenges, and unlock limitless growth.

Successful candidates must be able to commit to an onboarding date by the end of the year. Please state your availability and graduation date clearly in your resume.

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.

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.

Qualifications

Minimum Qualifications:

- Individuals who are completing or have recently completed a Bachelor's degree in Computer Science, Machine Learning or a related 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., Deep Speed, 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:

Job Information

The base salary range for this position in the selected city is $128000 - $316800 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 plan with company match, paid parental leave, short-term and long-term disability coverage, life insurance, wellbeing benefits, among others. Employees also receive 10 paid holidays per year, 10 paid sick days per year and 17 days of Paid Personal Time (prorated upon hire with increasing accruals by tenure).

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…