Senior Data Science Engineer / Senior Machine Learning Engineer (Applied Insights)
Japan’s largest mobile payments platform (~75M users); SoftBank/LY Corporation fintech JV; 40% equity holder of Binance Japan.
About PayPay
PayPay Corporation is a Tokyo-based fintech company operating Japan’s leading QR/mobile payment service, founded 2018 as a SoftBank/Yahoo Japan (LY Corporation) joint venture, with banking (PayPay Bank), insurance and securities offerings. In October 2025 PayPay acquired a 40% equity stake in Binance Japan, making the crypto exchange an equity-method affiliate.
Skills
About the Role
Own the end-to-end design, implementation, evaluation, and maintenance of production machine learning models for prediction, recommendation, and anti-fraud use cases. Lead architectural decisions, analyze and visualize user and merchant data, deliver insights that inform product strategy, and collaborate on robust production systems.
Requirements
- Bachelor's degree in a quantitative field such as Computer Science, Machine Learning, Mathematics, Statistics, Economics, or Physics, or equivalent.
- Verbal and written English communication skills; Japanese is beneficial for cross-functional collaboration.
- More than five years of experience as a data scientist, machine learning engineer, or equivalent.
- Experience with Python and SQL.
- Preferred: Master's or PhD, seven-plus years of experience, big data technologies, recommendation systems, deep learning, NLP, optimization, anti-fraud systems, AWS services, Databricks, Snowflake, A/B testing, hypothesis testing, microservices, and Japanese communication skills.
Responsibilities
- Own the end-to-end design, implementation, evaluation, and maintenance of machine learning models from problem framing through production.
- Lead architectural decisions for data science systems.
- Process, analyze, and visualize user and merchant data to provide insights that influence product strategy.
- Collaborate with data engineers, product managers, and stakeholders to build robust production systems.
Benefits
- Social insurance, including health, employee pension, employment, and compensation insurance.
- 401K.
- Language learning support.
- Translation and interpretation support.
- Visa sponsorship.
- Relocation support.
- Super flexible working hours with no core time.
- Annual leave of up to 14 days in the first year.
- Five personal leave days each year.
