Sr. Machine Learning Engineer

The opportunity
At Unity, we’re committed to building a culture grounded in Empathy, Respect, and Opportunity. Within our fast-paced and collaborative environment, we’re tackling complex challenges that drive meaningful impact for creators and users across our ecosystem. The Unity Demand Optimization team plays a central role in this effort by building ad campaign optimizations that enable advertisers to efficiently capture user engagement while minimizing their costs. The team leverages machine learning models to incorporate advertisers' off-site goals into auction ranking, helping them maximize installs, key conversions, or return on ad spend.

We are seeking a highly skilled staff engineer to take a critical role in building state-of-the-art bidding optimization systems that enable:

Efficient budget pacing across campaigns.

Automated bidding strategies that align with advertiser goals.

Continual system improvement through rigorous experimentation.

Sustainable growth for Unity’s advertising business.

What you'll be doing

• Design, implement, and maintain high-performance auto-bidding algorithms and advertiser-facing products (e.g., Target ROAS, Target CPA).


• Ensure these systems meet or exceed campaign performance goals, advertiser expectations, and system reliability standards.


• Lead development on core initiatives such as:


• A bid-based budget pacing system that ensures daily budget delivery.


• Maximize Conversions, which leverages real-time bidding to meet key advertiser goals.


• Lowest Cost, a product that automates bidding to simplify campaign management.


• Target ROAS, which lets advertisers scale volume without sacrificing performance targets.


• Drive best practices for model quality, experimentation, system reliability, and operational excellence.


• Actively participate and work with other leads to set the long term direction for the team, plan and oversee engineering designs and project execution.


• Effectively communicate complex technical concepts to non-engineering stakeholders.

What we're looking for

• Advanced degree (MS or Ph.D.) in Computer Science, Machine Learning, Statistics, or a related field—or equivalent practical experience.


• 5+ years of hands-on experience building and operating large-scale Ads delivery and optimization systems.


• 3+ years of experience building control systems, PID controllers, multi-armed bandits, reinforcement learning algorithms, or bid/pricing optimization systems.


• Significant experience in one or more general-purpose programming languages like Java, Python, Go, Scala, C++ or similar.


• Knowledge of metric design, experimentation methodologies, and large-scale data analysis.

You might also have

• Experience designing and productionizing optimization algorithms in an ad serving platform and/or other marketplaces.


• Experience with state of the art control systems, reinforcement learning algorithms.

Additional information

• Relocation support is not available for this position.

Life at Unity
We offer a wide range of benefits designed to support employees' well-being and work-life balance. You can read more about them on our career page .

Unity [NYSE: U] is the leading platform to create and grow games and interactive experiences. Creators, ranging from game developers to artists, architects, automotive designers, infrastructure experts, filmmakers, and more, use Unity to bring their imaginations to life across multiple platforms, from mobile, PC, and console, to spatial computing.

As of the third quarter of 2024, more than 70% of the top 1,000 mobile games were made with Unity, and in 2024, Made with Unity applications had an average of 3.7 billion downloads per month. For more information, please visit Unity .

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.

Pursuant to the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records.

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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