**The opportunity**

We are looking for a Senior Machine Learning Engineer to join our Vector Core Modeling team. In this role, you will design and build scalable machine learning systems that power ad ranking in large-scale advertising platforms.

As a key member of the Vector AI (https://unity.com/products/unity-ads/vector) group, you will play a central role in driving Unity’s ads engine. You will work with massive datasets and rich signals to develop the state-of-the-art ads models. These models serve as the core intelligence behind delivering the right ad to the right user at the right time, maximizing both user experience and advertiser outcomes.

**What you'll be doing**

+ Design, implement, and optimize the core ads models
+ Build and enhance multi-objective ranking systems balancing retention, monetization, diversity, and user long-term value
+ Solve cold-start problems for new users, new games, and new creatives
+ Conduct offline eva...