Senior Unity Developer Jobs in California (NOW HIRING)

The opportunity

At Unity, we are building a world-class ad-tech ecosystem that connects billions of users with the creators and experiences they love. The Advertiser Growth team is the engine of this mission, ensuring that as our marketplace expands, advertisers have the intelligent tools, robust infrastructure, and rigorous experimentation frameworks needed to scale their impact.
In 2026, our roadmap is defined by three transformative pillars: Foundation, Smart, and Intelligence. This role is unique in its technical breadth, sitting at the intersection of financial execution, creative innovation, and marketplace science. You will architect the GenAI systems that build high-performing creatives, design the pacing algorithms that manage multi-million dollar budgets, ensure our billing pipelines handle massive scale with zero-fault tolerance, and build the experimentation infrastructure that allows us to scientifically evolve the marketplace. This is a high-stakes role where your technical leadership directly governs Unity's financial integrity and the long-term growth of our ecosystem.

What you'll be doing

• Next-Gen budget pacing: Design and optimize sophisticated pacing controllers (PID, probabilistic forecasting) to smooth advertiser spend across diverse time zones and traffic spikes, ensuring optimal delivery and marketplace stability.
• Creative GenAI infrastructure: Lead the backend integration of Generative AI models (Diffusion, LLMs) to automate the creation of high-performing image and video assets tailored to specific campaign goals and formats.
• Marketplace experimentation engine: Build and scale the infrastructure for high-velocity experimentation, including A/B testing, switchback tests, and long-term holdouts to measure the impact of marketplace changes on advertiser ROI and platform health.
• High-Scale billing reliability: Architect and maintain high-throughput billing pipelines that process billions of events with 100% accuracy, bridging the gap between real-time ad delivery and mission-critical financial reconciliation.
• Scientific optimization: Analyze complex financial and marketplace datasets to refine the trade-off between spend velocity and advertiser performance, using experimentation results to tune pacing and billing logic.

What we're looking for

• Advanced degree in computer science or relevant engineering-related field or equivalent experience.
• 4+ years of software engineering experience, including 1+ year working on ads delivery systems.
• Extensive experience building and operating large-scale, low-latency backend systems using languages like Java, Go, or Scala.
• Deep familiarity with building or maintaining budget control systems, feedback loops, or spend-prediction algorithms.
• Proven experience building or scaling experimentation platforms, with a deep understanding of variance reduction, interference/network effects, and metric design in a marketplace context.
• A track record of working on "mission-critical" pipelines (like billing, payments, or clearinghouses) where data precision, idempotency, and fault tolerance are paramount.
• Experience or strong technical interest in building the backend workflows required to serve, scale, and store Generative AI models for creative asset generation.
• Proficiency with real-time stream processing (Kafka, Flink, or Spark) specifically applied to event-based charging and real-time performance feedback.
• A proven ability to lead complex, multi-quarter technical roadmaps and mentor senior engineers in a high-growth environment.

You might also have

• Experience embracing AI as a strategic advantage in engineering, following established best practices for code quality and security.

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 world's 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 www.unity.com.

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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