Software Engineer Intern (Recommendation Infra, Performance Efficiency) - 2027 Summer

TikTok; San Jose (CA); On-site; USD 51,000 - 73,000; Full time

Job summary

TikTok is offering an internship with the Recommendation System Infrastructure team, focused on building and evolving large-scale online serving and data infrastructure for recommendation systems. Interns will gain hands-on experience in high-performance C++ environments, working with GPU/CPU compute, data pipelines, and automation workflows.

Candidates pursue a Bachelor's (preferred for entry) or Master’s degree in CS, with strong systems programming skills in C++, Go, or Java, and an interest

Qualifications

• Pursuing Bachelor's degree in CS or related field.
• Strong systems programming skills in C++, Go, or Java.
• Experience building scalable backend or distributed systems.
• Solid understanding of data structures, OS, networking, and distributed systems fundamentals.
• Experience with performance analysis and large-scale service optimization.
• Strong ownership, problem-solving, and communication skills.

Responsibilities

• Design, build, and optimize high-performance online serving systems for large-scale global recommendation systems, improving business ROI, system efficiency, and serving quality.
• Improve the efficiency, reliability, scalability, and cross-regional consistency of recommendation system infrastructure.
• Identify and resolve system performance bottlenecks across CPU, memory, bandwidth, GPU, latency, throughput, and resource allocation.
• Drive cost optimization for large-scale recommendation serving, including compute resource utilization and performance improvements.
• Build reliable and efficient workflows and pipelines for automation on candidate generation, profile generation, feature processing, training data generation, and online development.

Skills

C++

Go

Java

Distributed systems

Performance analysis

Ownership & communication

Education

Bachelor's degree in Computer Science or related field

Master's degree in Computer Science (Preferred)

Tools

Flink

Spark

Kafka

Cpp tooling

Job description

About the Team

The Recommendation System Infrastructure team is responsible for building and evolving the large-scale online serving and data infrastructure that powers TikTok’s recommendation products globally.

Our mission is to deliver highly efficient, reliable, observable, and scalable infrastructure for recommendation systems. The team works closely with recommendation algorithm teams to accelerate strategy iteration, improve compute efficiency, optimize serving cost, and enable the next generation of AI-native and agentic engineering workflows.

We focus on core infrastructure challenges across online/nearline/offline modules on GPU/CPU, high-performance computing, data pipelines, observability, automation, system reliability, and cost optimization. Our systems are primarily built in C++, while broader infrastructure and automation work may also involve offline data processing frameworks such as Flink, Spark, or other large-scale data systems. A key direction of the team is to build round-the-clock closed-loop agentic systems that can observe, diagnose, plan, execute, verify, and continuously improve recommendation infrastructure and iteration workflows.

We are looking for talented individuals to join us for an internship. Our internship program offers students hands‑on experience, industry exposure, and opportunities to apply their knowledge to real-world challenges while building a strong foundation for personal and professional growth.

Interns will gain practical experience, explore potential career paths, and participate in social events, learning programs, and development workshops alongside industry professionals.

Candidates may apply to a maximum of two positions across Our Company and its affiliates globally. Applications will be considered in the order they are submitted.

Applications are reviewed on a rolling basis, so we encourage you to apply early. Please clearly state your availability in your resume, including your start and end dates.

Candidates who pass resume screening will be invited to participate in Our Company's technical online assessment.

Responsibilities

• Design, build, and optimize high-performance online serving systems for large-scale global recommendation systems, improving business ROI, system efficiency, and serving quality.
• Improve the efficiency, reliability, scalability, and cross-regional consistency of recommendation system infrastructure.
• Identify and resolve system performance bottlenecks across CPU, memory, bandwidth, GPU compute efficiency, serving latency, throughput, and resource allocation efficiency.
• Drive cost optimization for large-scale recommendation serving, including business-impact-based cost efficiency, compute resource utilization, and infrastructure-level or strategy-level performance improvements.
• Build reliable and efficient workflows and pipelines for automation on candidate generation, profile generation, feature processing, training data generation, and online development.

Qualifications

Minimum Qualification(s)

• Currently pursuing a Bachelor's degree in Computer Science or a related technical discipline.
• Strong programming skills in at least one systems programming language, such as C++, C, Go, or Java.
• Experience in building scalable backend systems, distributed systems, infrastructure systems, or high-performance online services.
• Solid understanding of data structures, algorithms, operating systems, networking, and distributed system fundamentals.
• Experience with performance analysis, system debugging, reliability improvement, or large-scale service optimization.
• Strong ownership, problem-solving ability, and communication skills.
• Ability to work effectively with cross-functional teams, including infrastructure teams, recommendation algorithm teams, and product/business-facing engineering teams.

Preferred Qualification(s)

• Currently pursuing a Master's degree in Computer Science or a related technical discipline.
• Experience with infrastructure for recommendation systems, search engines, advertising systems, machine learning systems, or large-scale online serving systems.
• Experience optimizing high-throughput, low-latency C++ services in production environments.
• Familiarity with profiling, benchmarking, performance tuning, capacity planning, resource efficiency improvement, and cost optimization.
• Experience with large-scale data processing systems such as Flink, Spark, Kafka, or similar frameworks.
• Experience building end-to-end automation systems based on AI agents, LLMs, workflow orchestration, or closed-loop engineering automation.
• Experience designing agentic workflows for system diagnosis, performance optimization, reliability improvement, change validation, or automatic execution.
• Experience with real-time data pipelines, online training, feature engineering, candidate generation, or recommendation system iteration workflows.

Job Information

【For Pay Transparency】Compensation Description (Hourly) - Campus Intern

The hourly rate range for this position in the selected city is $45- $45.

Benefits may vary depending on the nature of employment and the country work location. Interns have day one access to health insurance, life insurance, wellbeing benefits and more. Interns also receive 10 paid holidays per year and paid sick time (56 hours if hired in first half of year, 40 if hired in second half of year). Interns who are not working 100% remote may also be eligible for housing allowance.

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:

• 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.

About TikTok

TikTok is the leading destination for short-form mobile video. At TikTok, our mission is to inspire creativity and bring joy. TikTok's global headquarters are in Los Angeles and Singapore, and we also have offices in New York City, London, Dublin, Paris, Berlin, Dubai, Jakarta, Seoul, and Tokyo.

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.

TikTok Accommodation

TikTok 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/RA-request