Researching AI by day,
making music by night.
I'm Nick Z. Cai — an AI researcher & builder working across NLP, LLM safety and agentic systems, with a parallel life in music production and multimedia arts. Interested in trustworthy LLMs, agentic AI for real-world markets, and everything where AI meets sound.
Selected Work
Research, engineering and creative projects — from LLM safety benchmarks to agentic trading infrastructure to original songs.
Ustnlp16 at SemEval-2025 Task 9
Improving NLP model performance through imbalance handling and focal loss for food-hazard detection. Published in the Proceedings of SemEval-2025 (ACL Workshop).
LLM Persuasion Defense
Independent research at HKUST CSE (advised by Prof. Yangqiu Song): a reproducible multi-turn persuasion benchmark with a stateful attacker and stateless target, plus prompt defenses and attention-head gating.
Phenotype-to-Diagnosis with GNNs
Built at CSIC (Madrid): clinical notes standardized to HPO/Phenopackets, IC-IDF weighting and GNN disease embeddings to rank OMIM diagnoses, with a reproducible evaluation framework.
Agentic Market Infrastructure
Agentic AI systems for financial markets — an autonomous quantitative research agent, an agent-facing financial action layer, and a Rust-based Polymarket CLOB arbitrage bot.
Celestial Music Generation
At HKGAI: a generative model and app that composes music from traditional Chinese celestial concepts, plus a deployed web service for the MultiTalk multi-person video generation project.
Experience
Industry and research roles across Hong Kong, Spain, Japan and mainland China.
Student Researcher · Independent Project
Led Exploring Risks of Misleading Information from Chat Assistants and Countermeasures (advised by Prof. Yangqiu Song): multi-turn persuasion & defense evaluation with turn/order ablations, cross-backend cost & latency telemetry, prompt defenses and attention-head gating.
Research Intern
Developed a phenotype-to-diagnosis pipeline (HPO/Phenopackets, IC-IDF, GNN disease embeddings ranking OMIM) and a reproducible evaluation framework with automated sweeps, ROC AUC / Top-k recall reporting and ablations. Supervised by Dr. Monica Chagoyen.
Research Assistant
Built a generative AI model composing music from traditional Chinese celestial concepts; deployed the MultiTalk multi-person video generation service end-to-end — model inference, backend APIs and a frontend UI for job submission and monitoring.
Student Researcher · Special Course
Researched Wave Field Estimation in Acoustics using Physics-Informed Machine Learning: trained PINNs and Fourier Neural Operators to estimate room acoustics and spatial audio wave fields from limited data.
Programmer Intern
Designed musical and lexical Unity mini-games for language-learning research and built a complete music intervention system.
Research Intern
Researched error-correcting codes (Hamming & Reed–Solomon) in MATLAB with Prof. Hajime Matsui at the Information Communication Engineering Laboratory.
Business Manager Intern
Analyzed China Mobile's commodity purchases with Python and predicted enterprise purchase preferences via ML; designed algorithms to speed up procurement data processing across 27,000 goods.
Software Development Intern
Built computer-vision models detecting traffic violations at 95% accuracy; analyzed monitoring-system traffic data with SQL & Python to ease congestion in Hefei.
Education
MSc in Big Data Technology
GPA 3.99/4.3. Entrance, Excellent Student & Goertek Academic Excellence Scholarships. Independent projects in creative sound & video design and LLM safety.
BSc in Internet & Multimedia Technologies, Minor in Applied Mathematics
Dean's Honours List & Best Semester GPA Award (2021/22). Final year project: video scene analysis with key-feature emission using deep learning.
Honors & Beyond the Lab
🏆 Honors & Awards
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Runner-Up · W3 Algorand HackathonLed a team of 5 building the blockchain game "Universal Harvesters" in Unity (Univ. of Belgrade × Univ. of Florida)2023
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Goertek Academic Excellence ScholarshipHKUST2025–26
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Entrance & Excellent Student ScholarshipsHKUST2024–25
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Dean's Honours List & Best Semester GPAThe Hong Kong Polytechnic University2021–22
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Dr. Y.K. Ching Memorial ScholarshipFor curriculum design & remote teaching at 3 primary schools in Taiwan2021–22
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Special Recognition & Merit AwardsVideo production and poster design competitions, PolyU2023–24
🎭 Activities & Leadership
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Member · The University Choir, HKUSTBass 1, representing the university in performances2024–
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Young Future Energy Leader (2024 Cohort)Khalifa University, Abu Dhabi — global debates on sustainable energy2023–25
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Music Director · PolyU Hall ChoirOrganized music workshops and led choir performance coaching2021–22
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Global Student Ambassador · PolyU GSAPCross-cultural exchange and student affairs2022–23
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Curriculum Designer & Lecturer · HeartFire EducationDesigned and taught a remote curriculum for 3 primary schools in Taiwan2021–22
📜 Certifications
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Mental Health First Aid Standard CourseMental Health Association of Hong Kong2024
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The Art of Music ProductionBerklee College of Music (Coursera)2021
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Fundamentals of Music TheoryUniversity of Edinburgh (Coursera)2020
Skills
AI / Data
Engineering
Creative
Languages
Let's build something.
Open to research collaborations, engineering roles and creative projects — or just say hi.