Senior Full Stack Engineer - 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 are a Senior Engineer first, and an AI-builder second. While your output will be autonomous AI agents, the day-to-day responsibilities include building the robust, scalable, and secure distributed systems that allow those agents to operate. This role will join a "Tiger Team". You will own the full vertical-from the React frontend where humans supervise agents, to the Python/Go backend services that power them, down to the Kubernetes infrastructure they run on. Responsibilities To succeed in this role, you are expected demonstrate mastery of the following engineering fundamentals: 1. Backend Engineering & System Architecture - Language Proficiency: Expert-level fluency in Python (FastAPI, Django, or Flask) is mandatory for AI orchestration. - API Design: Extensive experience designing RESTful APIs and GraphQL schemas. You understand idempotency, rate limiting, authentication (OAuth2/JWT), and API versioning strategies. - Distributed Systems: Deep understanding of microservices architecture, message queues (Kafka, RabbitMQ, or SQS), and asynchronous task processing (Celery, Temporal). You know how to handle race conditions and ensure data consistency across services. - Database Design: - Relational: Expert SQL skills (PostgreSQL/MySQL). You can design normalized schemas, optimize complex queries, and understand indexing strategies for performance. - NoSQL: Familiarity with key-value stores (Redis for caching/session management) and document stores (MongoDB/DynamoDB) for flexible agent memory. 2. Frontend Engineering - Modern Frameworks: Deep expertise in React (TypeScript) ecosystems. You are comfortable using Next.js for server-side rendering and static site generation. - State Management: Proficiency with complex state management libraries (Redux Toolkit, Zustand, or React Query) to handle real-time agent status updates without UI lag. - UI/UX Implementation: Ability to implement responsive, accessible designs using modern styling systems (Tailwind CSS, Styled Components, or Material UI). You aren't just "patching" UIs; you build intuitive dashboards for non-technical operators. 3. Infrastructure & DevOps - Containerization: You live in the terminal. Experience writing multi-stage Dockerfiles and managing container orchestration with Kubernetes (Helm charts, kubectl). - CI/CD Pipelines: Experience setting up comprehensive CI/CD pipelines (GitHub Actions, GitLab CI) that include automated linting (flake8/black/ESLint), unit testing (PyTest/Jest), and integration testing before deployment. - Observability: You build systems that are easy to debug. Experience integrating observability tools (Prometheus, Grafana, Datadog, Sentry) to trace requests and monitor system health. The "AI-Native" Layer While the skills above are the foundation, the following are the "force multipliers" required for this specific team: - Vector Infrastructure: Experience running vector databases (Pinecone, Weaviate, Milvus) in production, including hybrid search (keyword + semantic) strategies. - Agent Orchestration: Practical experience with LangChain or LangGraph to manage agent state, memory, and tool execution loops. - LLM Integration: Deep familiarity with OpenAI/Anthropic APIs, specifically Function Calling (structured output) and context window management.

Qualifications

Minimum Qualifications - 5+ years of experience in software development with a strong focus on backend systems. - Proven proficiency in full stack web development using languages like Python and JavaScript for building robust, scalable applications. - Demonstrated ability to work collaboratively and drive technical initiatives independently in a dynamic, fast-paced environment. Preferred Qualifications - Proficiency in Go (Golang) for high-concurrency microservices. - Experience in designing or developing automation agents or similar intelligent systems. - Demonstrated ability to contribute to architectural design, translate business goals into a technical vision, and make sound, data-driven decisions. - Experience with user interface designing keeping user experience at the forefront.

Job Information

[For Pay Transparency]Compensation Description (Annually)

The base salary range for this position in the selected city is $187040 - $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.

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.

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