Software Engineer, iOS - Securing Engineering, USDS

TikTok USDS Joint Venture; San Jose (CA); On-site; USD 187,000 - 360,000; Full time

Benefits offered by this job

Medical, dental, vision insurance

401(k) with company match

Paid parental leave

Wellbeing benefits

10 holidays per year

17 days of Paid Personal Time

Job summary

TikTok USDS Joint Venture LLC is seeking a Software Engineer for the Apple Platforms team to lead the AppGuard security framework across iOS and macOS. You will design and implement high-performance DSL-based engines for real-time security decisions and build tooling for sandbox components, collaborating with cross-functional teams to balance security with user experience.

The role emphasizes greenfield development, memory and network optimization, and a deep focus on performance on Apple

Qualifications

• BS/MS degree in Computer Science, Engineering, or a related field.
• 3+ years of experience in mobile and desktop app development for Apple platforms.
• Expertise in Objective-C and Swift, with a deep understanding of Darwin-based frameworks and system-level tools.
• Performance optimization: memory management, network optimization, and battery efficiency.

Responsibilities

• Architect Security Solutions: Own the technical direction for AppGuard, from design to iOS/macOS implementation.
• Traffic & Policy Control: Develop capabilities to monitor and cut-off app traffic based on dynamic rules and sampling.
• Performance Engineering: Implement high-performance engines to execute DSL-based logic for real-time security judging.
• Tooling Development: Design and develop platforms for integration, testing, validation, and profiling of sandbox components.
• Collaborate Cross-Functionally: Ensure security solutions meet operational needs without compromising user experience.

Skills

Apple platforms skills

Mobile & desktop app dev

Objective-C & Swift

Darwin frameworks

Performance optimization

Education

BS/MS in CS or Eng

Tools

Network Extensions

System-level traffic filtering

Cursor

Replit

Job description

Responsibilities

About the team

The Security 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. This team is 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.

Responsibilities

We are seeking a Software Engineer to be a core member of our Apple Platforms team. In this role, you will lead the design and development of an AppGuard security framework, specifically focusing on the monitoring and management of all egress/ingress traffic. You will be a key contributor in a greenfield environment, applying high-performance engines and Domain-Specific Languages (DSL) to ensure application assurance.

• Architect Security Solutions: Take ownership of the technical direction for AppGuard, from initial design to implementation on iOS and macOS.
• Traffic & Policy Control: Develop capabilities to monitor and cut-off application traffic based on dynamic rule updates and sampling
• Performance Engineering: Implement high-performance engines to execute DSL-based logic for real-time security judging.
• Tooling Development: Design and develop associated platforms for the integration, testing, validation, and profiling of sandbox components.
• Collaborate Cross-Functionally: Work with stakeholders to ensure security solutions meet operational needs without compromising user experience.

Qualifications

Minimum Qualifications

• BS/MS degree in Computer Science, Engineering, or a related field.
• 3+ years of experience in mobile and desktop app development for Apple platforms.
• Expertise in Objective-C and Swift, with a deep understanding of Darwin-based frameworks and system-level tools.
• Performance Optimization: Proven experience with memory management, network optimization, and battery efficiency.

Preferred Qualifications

• Hands-on experience with Network Extensions or system-level traffic filtering.
• Demonstrated ability to contribute to architectural design and translate business security goals into technical vision.
• Familiarity with AI-enabled development tools (e.g., Cursor, Replit) to accelerate core logic implementation.

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 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 $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;
3. Exercising sound judgment.