Senior Software Engineer - PaCI foundation and Platform AI - USDS

Responsibilities
About the Team
The USDS JV Platform and Community Integrity (PaCI) team is the architectural backbone of TikTok's Risk & Integrity ecosystem in the U.S. We drive end-to-end integrity for TikTok and its expanding ecosystem, including Lemon8 and emerging affiliate platforms, by leveraging localized U.S. data and state-of-the-art AI/LLM capabilities.

Within this organization, the PaCI Foundation and Platform AI team builds and maintains TikTok's U.S. risk control ecosystem. Our mission is to deliver core risk management systems, anti-automation fraud tools, and threat intelligence pipelines. We architect the core machine learning infrastructure and risk AI platforms required to protect our billion-user ecosystem from complex, adversarial threats. Joining our team offers engineers the unique opportunity to develop, automate, and validate large-scale distributed systems while tackling the intricate engineering challenges of global scale.

Responsibilities
As a core engineer on our team, you will own the full-lifecycle engineering of our foundation systems and AI platforms. You will:
- Develop, implement, and maintain high-throughput, low-latency systems such as Decision Engines, Data Platforms, and Horizontal ML/AI architectures. Write clean, production-ready backend code (Go/C++/Python) to serve defense algorithms at a global scale.
- Work on infrastructure and tools to enable the construction, deployment, and serving of risk defense algorithms and machine learning models at scale. Improve capacities for risk prevention, perception, and remediation across various TikTok businesses. Work closely with cross-functional partners to understand business needs and design effective platform solutions.
- Drive the day-to-day development, operations, and technical excellence of the platform, and continuously improve performance, reliability, and scalability.
- Design and implement robust automated testing frameworks, regression suites, and stress-testing tools for complex distributed systems and LLM behaviors. Leverage next-gen AI Agent capabilities to build advanced test automations.
- Keep risk control solutions state-of-the-art regarding data security, modularization, privacy, and compliance.

Qualifications
Minimum Qualifications
- Bachelor's degree, majoring in Computer Science or related fields
- 3+ years of experience designing, building, and maintaining large-scale distributed systems.
- Proficiency in one or more general-purpose languages, such as Go, C/C++, Java, or Python.
- Problem Solving: Ability to think critically and decompose complex, ambiguous problems into clear, concise technical solutions.
- Exceptional communication skills with a history of working effectively in cross-functional, multi-regional environments.

Preferred Qualifications
- MS or PhD in Computer Science, Computer Engineering, or a related technical field.
- Hands-on experience with high-throughput low latency infrastructure handling massive traffic (e.g., feature stores, model serving, or AI infra etc).
- Background in Risk, Anti-Fraud, AI Safety or Trust & Safety domains.

About USDS
TikTok USDS Joint Venture LLC is dedicated to the safety and security of millions of Americans who create, discover, and connect with what they love on the apps we operate. The Joint Venture has been established in compliance with the Executive Order signed by President Trump on September 25, 2025. Our foundation is a comprehensive data privacy and cybersecurity program we operate under defined safeguards to protect national security and secure U.S. user data, apps and the algorithm. We safeguard the U.S. content ecosystem, holding decision-making authority for trust and safety policies and moderation. USDS Joint Venture helps ensure Americans can continue to express their creativity, discover new hobbies and interests, and build thriving communities and businesses on a global scale.​
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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.​
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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 https://tinyurl.com/USDS-RA​


Job Information
【For Pay Transparency】Compensation Description (Annually)
The base salary range for this position in the selected city is $136800 - $359720 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.​