【上場ITサービス企業】データサイエンティスト （8209)

A Global IT Service firm is looking for a Data Scientist in The Advertising Division.
With the practical adoption of AI, decision-making in ad serving is becoming faster and more sophisticated, and competition among platforms is intensifying. In this context, our ad serving platform (RUNA) is in a phase of differentiating itself by strengthening the in-house development of core algorithms centered on price optimization, ad performance maximization, and creative optimization. 

Responsibilities:
- Problem definition for ad delivery optimization and the design of KPIs/metrics, along with observability (dashboards and alerts).
- Data preprocessing, feature engineering, modeling, and offline evaluation (including simulation) for price optimization, CTR/CVR and value prediction, and creative optimization.
- Online deployment and experiment design: A/B tests/bandits, calibration, rollout strategy planning, effectiveness evaluation, and continuous improvement.
- Production operations and MLOps: building training/inference pipelines; monitoring and drift detection; model updates and automated rollback; quality and privacy governance.
- Collaboration with internal stakeholders (product, engineering, sales/operations) on requirements definition, decision support, documentation, and knowledge sharing.

Required skills:
- 3+ years of hands-on experience in data analysis and machine learning using Python and SQL; proficiency with Pandas/NumPy/scikit-learn and data visualization tools
- Experience processing large-scale data (e.g., Spark, BigQuery) and building reproducible analytics environments (using notebooks and repositories together, code reviews, testing)
- Solid foundation in statistics, probability, causal inference, and experimental design (hypothesis testing, sampling, A/B test design and analysis, effect size estimation)
- Experience developing machine learning models (regression, classification; tree-based methods/GBDT/logistic regression/simple neural networks) with rigorous evaluation design (offline/online metrics, calibration)
- Foundational knowledge of online/digital advertising (CTR/CVR prediction, bidding and budget pacing, ad serving control, KPI optimization) or practical optimization experience in adjacent domains
- Feature engineering oriented toward price and serving optimization use cases; data quality management, leakage prevention, and handling delayed/late-arriving labels
- Production experience (model deployment, scheduling/pipeline operations, monitoring, implementing and operating drift detection)
- Communication skills for collaborating with stakeholders on requirements definition, analysis design, and decision support (including explaining and visualizing deliverables)

Why should you apply:
- This is a long-term opportunity with a chance to become a permanent employee 
- You will be working with international team members 
- Free breakfast, lunch and dinner at the cafeteria 


Company Details: 
A global company with a strong presence in multiple business areas. It has achieved sustained growth both domestically and internationally, including in the U.S. and Europe. The company boasts a diverse and international environment and is committed to equal opportunity, offering a wealth of career opportunities. Due to the diverse nature of our business, we handle a wide range of technologies! You can also choose the environment you are most comfortable with, such as Windows/Mac! Meals in the company cafeteria are also free. Our chefs are always coming up with new menu items, so you can enjoy your meal without getting bored!

Working hours: 9:00 - 17:30 (Mon-Fri)
Working Style: Hybrid (4 days in office, 1 day work from home)
Holidays: Saturday, Sunday, and National Holidays, Year-end and New Year Holidays, Paid Holidays, Other Special Holidays
Services/Benefits: Social insurance, DC Pension Plan, Transportation Fee, Skillhouse University, Test payback system, and more