Software Engineer, LLM - USDS

Responsibilities

About the Team The Cyber Defense & Engineering team is missioned to run and operate security infrastructures, platforms and technologies, as well as to support cross-functional teams to protect our users, products and infrastructures. In this team you'll have a unique opportunity to have first-hand exposure to the strategy of the company in key security initiatives, especially in deploying and maintaining scalable and secure-by-design systems and solutions. Our challenges are not your regular day-to-day technical problems; you'll be part of a team that's developing new solutions to new challenges of a kind not previously addressed by big tech. It's working fast, at scale, and we're making a difference. About the Role You'll be an integral part of the USDS Cyber Defense & Engineering team, responsible for enhancing security tools and identifying vulnerabilities, with a specific focus on content assurance and the application of large language models (LLMs). You'll collaborate cross-functionally with partners inside and outside TikTok to fortify our products and users' security, helping to establish TikTok as the most trusted platform. We are seeking a versatile, forward-thinking, and outcome-driven Software Engineer to propel our projects forward. In this capacity, you will engage with diverse technical and non-technical teams across various regions, contributing to the development of innovative, AI-driven solutions to complex content moderation challenges. If you thrive in a dynamic environment and relish the opportunity to shape the strategic trajectory of a large global organization, this role offers an exciting prospect. The ideal candidate will possess demonstrated problem-solving abilities, sound business acumen, and a track record of collaborating with multiple teams to successfully deliver projects. They should exhibit a genuine passion for safeguarding the security and privacy of our users, and a strong understanding of how to leverage cutting-edge technology, like LLMs, to achieve that goal. Responsibilities - Collaborate Across Teams: Work closely with data scientists, software engineers, machine learning engineers, and product managers to understand the recommendation engine. - Deep Expertise in Recommender Systems: Leverage your expertise in machine learning and coding to gain an in-depth understanding of context-aware recommender systems. - Understand Core System Components: Understanding of key modules in the recommender system, including recall, ranking, and reranking, ensuring high-quality, personalized recommendations at scale. - End-to-End Ownership: In-depth understanding of the complete lifecycle of machine learning systems, from building and maintaining data pipelines and feature engineering, to training models and integrating them seamlessly into production environments. - Ensure Security & Compliance: Work with cybersecurity teams to ensure that the recommender systems align with compliance standards and implement practices that enhance user trust and experience. - Support Automation & Prototyping: Contribute to quick prototyping and proof-of-concept initiatives that automate rule reviews within the recommendation systems, ensuring both efficiency and compliance. - Document & Ensure Accessibility: Build and maintain comprehensive documentation for data processes and machine learning models, ensuring transparency, accessibility, and consistency across teams.

Qualifications

Minimum Qualifications: - Bachelor's degree or PHD. in Computer Science, Engineering, Mathematics, or a related field along with Experience in Recommendation Systems: Proven track record of designing, developing, and optimizing recommendation systems, particularly at scale. - Machine Learning Expertise: Experience working with machine learning frameworks such as TensorFlow, PyTorch, scikit-learn, MXNet, or similar tools to build and deploy models. - Hands-on experience in one or more of the following areas: Large Language Models (LLM), Machine Learning, Deep Learning, Recommender Systems, Data Mining, or Natural Language Processing - Strong Programming Skills: Excellent programming skills, data structure and algorithm skills, proficient in C/C++ or Python programming language, candidates with awards in ACM/ICPC, NOI/IOI, Top Coder, Kaggle and other competitions are preferred. - Solid Understanding of Algorithms: Deep knowledge of data structures, algorithms, and optimization techniques to solve complex technical challenges along with Problem-Solving Mindset: Excellent troubleshooting and debugging skills, with an ability to quickly address issues that arise in live environments. - Collaboration & Communication: Strong teamwork and communication skills, with the ability to work effectively across interdisciplinary teams and clearly explain complex technical concepts. Preferred Qualifications - Master's degree or PHD. in Computer Science, Engineering, Mathematics, or a related field along with Experience in Recommendation Systems: Proven track record of designing, developing, and optimizing recommendation systems, particularly at scale. - Advanced Techniques: Experience with advanced recommendation algorithms such as matrix factorization, collaborative filtering, or deep learning-based methods. - Production-Ready Systems: Hands-on experience in deploying machine learning models in production environments, with an understanding of scaling and performance tuning. - Model Evaluation: Familiarity with model evaluation metrics (e.g., precision, recall, NDCG) and A/B testing to assess and improve system performance. - Cloud & Containerization Expertise: Knowledge of containerization tools (Docker, Kubernetes) and microservices architecture to support scalable, distributed systems. Security Awareness: Understanding of security and compliance best practices for handling user data in machine learning applications.

Job Information

[For Pay Transparency]Compensation Description (Annually)

The base salary range for this position in the selected city is $118657 - $259200 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 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 USDS

TikTok is the leading destination for short-form mobile video. Our mission is to inspire creativity and bring joy. U.S. Data Security ("USDS") is a subsidiary of TikTok in the U.S. This new, security-first division was created to bring heightened focus and governance to our data protection policies and content assurance protocols to keep U.S. users safe. Our focus is on providing oversight and protection of the TikTok platform and U.S. user data, so millions of Americans can continue turning to TikTok to learn something new, earn a living, express themselves creatively, or be entertained. The teams within USDS that deliver on this commitment daily span across Trust & Safety, Security & Privacy, Engineering, User & Product Ops, Corporate Functions and more.

On-site presence across teams allows the company to operate with greater speed, alignment, and agility - especially in areas like real-time decision-making, team development, and integrated execution. As such, the company is shifting from a hybrid work model to a fully in-person schedule up to 5 days a week.

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.

USDS Reasonable Accommodation

USDS 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