Lik
Machine Learning Engineer at Amazon
Chinese, English, Japanese & MalayMachine Learning Engineer with 7+ years of experience designing and deploying large-scale recommendation and search systems serving millions of users.
- Chinese, English, Japanese & Malay
Tokyo, Japan
About Me
I've led development of graph neural network–based recommenders and LLM-powered analytics systems, owning modeling, offline/online evaluation and production deployment across AWS and Databricks, with a strong focus on measurable impact through experimentation.
Before Amazon I built search ranking and coupon recommendations at PayPay, a pricing engine and data platform at Walmart, and large-scale data pipelines at Yahoo. I hold an M.S. from the University of Tokyo and AWS (ML, Architect, DevOps, Data Engineer) and Azure certifications.
Skills & Expertise
- Python
- Scala
- Go
- SQL
- PyTorch
- TensorFlow
- Spark
- OpenSearch
- Kubernetes
- Docker
- ML System Design
- Recommender Systems
- Search & Ranking
- LLMs
- Airflow
- SageMaker
- Databricks
- AWS
- Azure
Career Background
- Oct 2024 – Present
Machine Learning Engineer
AmazonGraphSAGE recommender with 2× offline nDCG@10 and +48% catalog coverage across 17 retail categories; multi-agent LLM Text-to-SQL platform used for Weekly Business Review reporting.
- Apr 2023 – Sep 2024
Machine Learning Engineer
PayPayEnd-to-end search ranking for PayPay Nearby (+13% DAU); two-stage retrieval + learning-to-rank; personalized coupon recommendations (+30% DAU in A/B tests).
- May 2021 – Mar 2023
ML & Data Platform Engineer
WalmartEvent-driven pricing engine for Walmart Online Grocery on Azure/Databricks (200% improvement); data platform with Delta Live Tables, MLflow and Spark.
- Apr 2019 – Apr 2021
Data Engineer
Yahoo"Featured Popularity Ranking" for PayPay Mall with Spark ML; ML platform on Kubernetes; Airflow ETL over 4PB.
- Apr 2017 – Mar 2019
Research Collaborator
Japan Atomic Energy AgencyFirst-principles model of polyalcohol dehydration in hot water on 200 CPU cores; published paper.