Responsibilities

Join Tik Tok Ads Core - the powerhouse behind one of the world's largest advertising ecosystems. As a Senior Backend Engineer, you'll play a critical role in designing and scaling the high-performance systems that serve billions of ad requests daily. This is a high-impact role suited for engineers who thrive in solving complex system challenges and want to contribute at the intersection of technology, product innovation, and global scale.

Why Join Us?

As a senior engineer on our team, you will:

1. Drive Technical Excellence in a Global, Mission-Critical System
   Take ownership of backend infrastructure powering real-time ad delivery at global scale. You'll lead efforts to optimize system architecture, improve response times, and ensure reliability under extreme concurrency.

2. Lead Innovation Across Ad Products and Formats
   Collaborate closely with product, engineering, and design teams to launch cutting-edge ad formats. You'll help shape technical direction across diverse content domains, enabling the platform to meet evolving business and user needs.

3. Solve Deep Technical Challenges at Scale
   Architect and implement resilient, distributed systems capable of handling massive throughput with millisecond-level latency. You'll address complex problems around data consistency, system fault tolerance, service degradation, and observability.

4. Mentor and Influence
   Set the bar for engineering best practices. Mentor junior engineers, contribute to internal knowledge sharing, and lead discussions on performance tuning, system design, and long-term technical strategy.

5. Be a Strategic Partner
   As a senior contributor, you'll be involved early in product and technical planning. Your insights will help prioritize features, identify risks, and drive key architectural decisions aligned with long-term growth and scalability.

Key Responsibilities

• Lead the design, development, and optimization of high-concurrency backend services for global ad delivery.
• Identify and solve complex technical challenges in distributed systems, with a focus on scalability, performance, and fault tolerance.
• Collaborate across product, infrastructure, and data teams to deliver robust solutions that support new ad formats and business growth.
• Drive continuous improvements through code quality, architectural reviews, and technical mentorship.
• Contribute to the evolution of coding standards, operational practices, and internal technical tooling.

Qualifications

Minimum Qualifications

• Strong computer science fundamentals and proven ability to deliver production-grade backend systems at scale.
• Proficiency in at least one backend programming language (Go, Java, Python, or C++).
• Solid understanding of core infrastructure components such as MySQL, Redis, message queues, and Nginx, including experience in tuning for high-load environments.
• Experience designing and maintaining large-scale, distributed, high-availability services.
• Excellent communication and collaboration skills; able to lead initiatives and work cross-functionally in a global setting.

Preferred Qualifications

• Deep expertise in Golang and system-level optimization.
• Prior experience in building and scaling ad delivery systems, recommendation engines, or other real-time systems with extreme concurrency.
• Experience with observability and troubleshooting tools for large-scale backend systems.
• Track record of driving large cross-team engineering initiatives.
• Passion for mentoring, setting technical direction, and driving team-wide improvements.

Compensation

The base salary range for this position in the selected city is $187,040 - $359,720 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

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
• 401(k) savings plan with company match
• Paid parental leave
• Short-term and long-term disability coverage
• Life insurance
• Wellbeing benefits
• 10 paid holidays per year
• 10 paid sick days per year
• 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.

Additional Information

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:

• Interacting and occasionally having unsupervised contact with internal/external clients and/or colleagues;
• Appropriately handling and managing confidential information including proprietary and trade secret information and access to information technology systems; and
• Exercising sound judgment.