AI Agent Algorithm Engineer Intern (Global E-Commerce, Conversational AI) - 2027 Start (PhD)

Responsibilities About the Team

We build the next-generation unified Agent system for TikTok's global e-commerce customer service — running in 30+ languages across one of the largest e-commerce surfaces on the internet. Our north star is a self-evolving Agent, where post-training, harness, memory / context engineering, tools, and evaluation form one closed loop, and every served conversation becomes the next iteration's training / eval / retrieval / skill-induction signal. We build the agent runtime itself — Codex / Claude-Code-class — not prompts on top of a vendor API. As a new grad, you'll own a real end-to-end piece from day one and ship it to production.

We are looking for talented individuals to join us for an internship. PhD internships at Our Company provide students with the opportunity to actively contribute to our products and research, as well as to the organization's future plans and emerging technologies.

Our dynamic internship experience blends hands-on learning, enriching community-building and professional development events, and collaboration with industry experts.

Applications will be reviewed on a rolling basis, so we encourage you to apply early. Please clearly state your availability in your resume (Start date, End date).

Job Responsibilities

• Build and evolve the agent runtime (harness / agent loop) powering our customer-service agents — orchestrate skills, tools, and context; implement loop control & intervention, progressive disclosure, and behavior-level guardrails.
• Engineer context & memory for long multi-turn agents — agentic memory (structured note-taking), context compaction / summarization, context editing / observation masking, and just-in-time (retrieve-then-load) retrieval.
• Post-train and fine-tune LLMs (SFT / DPO / RL) and build the data flywheel that turns served conversations into training / eval / retrieval signals.
• Design and integrate tools, Skills, and MCP connectors (tools-as-APIs), plus skill / tool search for large tool inventories.
• Build evaluation — LLM-as-judge with human-agreement calibration; regression / safety / cost / latency-aware harnesses; close the offline↔online gap.
• Build the self-evolving loop — replay + user-simulator + Auto-RCA / Auto-GSB / Auto-Policy — so the system continuously improves itself.
• Own one high-leverage end-to-end surface and ship it to production across 30+ languages, measured on real business metrics (CSAT, resolution / containment rate).

Qualifications Minimum Qualifications

• Currently Pursuing a PhD in Software Development, Computer Science, Computer Engineering, or a related technical discipline.
• Strong Python plus one of C++ / Go / Rust / Java
• Solid ML / DL / NLP fundamentals, with genuine hands-on experience with LLMs or agents (coursework, research, internship, competition, open-source, or a serious side project)
• Able to read a paper or an engineering blog and turn it into working code

Preferred Qualifications

• Have built the runtime, not just called an API — even at research / hobby / competition scale: your own agent loop / harness, a memory / context-management system, a RAG or tool-use agent, or a fine-tuned / post-trained model
• Hands-on experience in any one of: post-training (SFT / DPO / RLHF / RLAIF / RLVR, reward modeling); agent systems (harness, context engineering, MCP / Skills, sub-agents, tool search); evaluation (LLM-as-judge, τ-bench / SWE-bench / GAIA / BFCL); inference & serving (vLLM / TensorRT-LLM, MoE, KV / prompt caching); or multilingual NLP — depth in one is enough, breadth welcome
• Publications, strong competition results (ACM-ICPC / Kaggle / ML competitions), or notable open-source contributions

Job Information

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.