Work & Experience
Senior ML Engineer building LLM-powered agentic systems, post-training pipelines, and evaluation infrastructure at scale.
Skills & Focus
Modeling & Methods
SFT, DPO/RLAIF, LoRA, Reward Modeling, RAG, Prompt Engineering, Red-Teaming
Focus Areas
LLM Post-Training, Agentic AI, Evaluation, Alignment, Synthetic Data
Systems & Infra
Multi-Agent Orchestration, Tool-Use Pipelines, Sandboxed Code Execution, CI/CD for ML
Languages & ML Stack
Python, Swift, C++, TypeScript · PyTorch, vLLM, Ray, Weights & Biases
Work Experience
Senior Machine Learning Engineer
Sep 2024 - Present Current
- Drove post-training iteration loops (SFT → DPO/RLAIF → reward modeling) end-to-end, coordinating data curation, training runs, and deployment gating for models serving 1B+ devices.
- Designed and delivered synthetic data pipelines (scenario generation, preference pairs, reward signals) that raised alignment pass rates from ~60% to 92%+ on internal safety benchmarks.
- Shipped a fault-tolerant Natural-Language-to-Python platform spanning 2,000+ user intents, architecting a multi-stage system of semantic clustering, tool generation, and sandboxed code synthesis.
- Achieved ~95% tool-calling accuracy on held-out multi-step agentic workflows by developing a rigorous evaluation harness with zero-shot testing, adversarial perturbations, and argument fuzzing.
- Architected a meta-prompting self-improvement engine that turns failure patterns into automated remediation, reducing manual diagnostics and resolution effort by ~85%.
- Built a unified evaluation framework with dataset versioning and a metric registry to consolidate disparate data stacks, enabling reproducible, traceable comparisons across all models and agents.
- Led red-teaming sprints and built automated adversarial probing for jailbreak, prompt-injection, and policy-violation detection across agentic workflows.
- Mentored junior engineers on evaluation-driven development and contributed to cross-org alignment standards for LLM safety and quality.
Machine Learning Engineer II
- Improved tool retrieval and query-to-program quality (+10% recall, −30% hallucinations) through RAG, LoRA/SFT on large models, prompt optimization, and user-simulation evals — early contributions to Apple Intelligence.
- Built synthetic data and evaluation pipelines for intent understanding, enabling rapid iteration on LLM-driven features across Siri and system-level intelligence.
- Increased OS update success rate by +25% by developing time-series forecasting models to smooth peak server loads and reduce resource contention failures.
- Co-inventor on three U.S. patents covering sensor-driven display power control and predictive energy management.
Machine Learning Engineer
- Built on-device ML models for intelligent charging and background scheduling using device-state signals under strict privacy constraints, improving battery-health outcomes without cloud data.
- Enabled Apple ProRes video on iPhone 13 Pro/Max by optimizing background task scheduling within power and thermal budgets.
Game Software Engineer
- Unity editor tools and real-time inspectors; ~3x designer workflow speed-up; shipped to titles serving 2M+ DAU.
Software Engineer
- Spring Boot/Node.js monitoring for millions of instruments; Oracle SQL optimized ~120s → ~3s; led a 6-person LSTM prototype for predictive monitoring.
Patents & Awards
Patents
- U.S. Patent No. 12,141,012 — Energy saving for battery powered devices (2024)
- U.S. Patent No. 12,436,593 B2 — Sensor-based display power control (2025)
- U.S. Patent No. 12,436,594 B2 — Predictive display power control (2025)
Academic Honors
- Dean's Honors List, The University of Hong Kong (2015-2019)
- CLP "Powering a Sustainable Generation" Scholarship (2017)
- Zhiyuan Scholarship (Soong Ching Ling Foundation) (2015)
Education
University of California, Berkeley
2019 - 2020M.Eng. in Electrical Engineering & Computer Science
The University of Hong Kong
2015 - 2019B.Eng. in Computer Science (First Class Honors)
Princeton University
2017Exchange Student in Computer Science
The first principle is that you must not fool yourself —
and you are the easiest person to fool.