Machine Learning Engineer, Next-Generation Recommendation Systems (New Grad PhD)

The opportunity
Unitys Vector AI team builds the machine learning systems that decide which ads reach which players across billions of monthly users on the worlds leading game engine. Recommendation and ranking systems are the core of this work: predicting user value optimizing bids and delivering outcomes for advertisers at massive scale.

We are building the next generation of these systems. The frontier has shifted large language models reinforcement learning from human feedback and agentic AI are reshaping what recommendation systems can do. We are looking for PhD graduates who have worked at that frontier and want to bring those ideas into production systems that matter.

What youll be doing

• Design build and evaluate next-generation ranking and recommendation models that incorporate LLMs RLHF and preference learning to improve ad relevance and user experience.
• Develop user understanding systems conversion prediction behavioral modeling and value estimation that operate across billions of impressions.
• Apply reinforcement learning and optimization techniques to bidding strategy auction dynamics and real-time ad delivery.
• Design and run rigorous experiments using causal inference A/B testing and offline evaluation frameworks to measure and improve model quality.
• Partner with engineering to bring research ideas into production working across the full pipeline from training data to deployed model.
• Communicate findings clearly to technical and non-technical stakeholders across engineering product and business teams.

What were looking for

• PhD in Computer Science Machine Learning Statistics or a related field (graduating 2026 or recent graduate).
• Strong research foundations in one or more of: recommendation systems reinforcement learning LLM post-training or alignment human-AI collaboration probabilistic modeling or optimization.
• Experience working with large-scale data and ML systems whether through research or industry internships.
• Fluency in Python; familiarity with ML frameworks such as PyTorch or TensorFlow.
• A track record of rigorous high-quality research publications at top venues (NeurIPS ICML ICLR KDD RecSys ACL WWW or similar) are a strong signal.
• Strong written and verbal communication skills able to make complex ideas accessible across technical and non-technical audiences.

You might also have

• Industry experience in ads recommendation or user understanding systems (internship experience counts).
• Hands-on experience with production ML pipelines training at scale feature engineering or experimentation infrastructure.
• Experience applying LLMs or generative models to ranking retrieval or structured prediction problems.
• Familiarity with agentic AI approaches multi-step reasoning tool use or human-AI collaboration frameworks.
• Exposure to causal inference uplift modeling or A/B testing at scale.
• Genuine curiosity about applied research and the drive to see ideas through to impact.

Additional information

• Relocation support is not available for this position

Benefits
At Unity we want our team members to thrive. We offer a wide range of benefits designed to support well-being and work-life balance.

Please note: Benefits eligibility specific offerings and coverage vary based on the country and employment status.

While specific benefits vary here are some of the ways we strive to take care of our eligible team members globally: Comprehensive health life and disability insurance Commute subsidy Employee stock ownership Competitive retirement/pension plans Generous vacation and personal days Support for new parents through leave and family-care programs Office food snacks Mental Health and Wellbeing programs and support Employee Resource Groups Global Employee Assistance Program Training and development programs Volunteering and donation matching program

Life at Unity
Unity NYSE: U is the worlds leading game engine powering play for more than 3 billion consumers each month. The top mobile games in the world the most played PC indie titles the most innovative console games and virtually all of the top XR and Web Games are developed deployed and grown in Unity. Unity also enables teams across industries like automotive manufacturing and healthcare to design simulate and collaborate in 3D closing the gap between ideas and reality. For more information please visit .

Unity is a proud equal opportunity employer. We are committed to fostering an inclusive innovative environment and celebrate our employees across age race color ancestry national origin religion disability sex gender identity or expression sexual orientation or any other protected status in accordance with applicable law. Our differences are strengths that enable us to support the growing and evolving needs of our customers partners and collaborators. If you have a disability that means there are preparations or accommodations we can make to help ensure you have a comfortable and positive interview experience please fill out this form to let us know.

This position requires the incumbent to have a sufficient knowledge of English to have professional verbal and written exchanges in this language since the performance of the duties related to this position requires frequent and regular communication with colleagues and partners located worldwide and whose common language is English.

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