Sr. Machine Learning Engineer jobs at Unity in United States, San Francisco

These models power our ad ranking and recommendation systems, helping advertisers reach the right users at the right time by accurately estimating engagement and conversion likelihood. By leveraging large-scale behavioral data, creative features, and contextual signals, we continuously improve the relevance and accuracy of our predictions. This drives key outcomes such as higher user engagement, stronger conversion performance, and better return on ad spend — enabling advertisers to achieve their goals while delivering a better experience for users.

• Design, implement, and maintain high-performance fraud detection models to identify and block fraudulent activities at the publisher, game, and user levels.
• Build and refine systems to analyze user behavior, transaction patterns, and contextual signals, enabling accurate and timely detection of suspicious or malicious activity.
• Ensure model quality and reliability by continuously monitoring performance, calibrating predictions, and addressing data drift or delayed feedback.
• 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.

• Advanced degree (MS or Ph.D.) in Computer Science, Machine Learning, Statistics, related field, or equivalent practical experience.
• 5+ years of hands-on experience building and operating large-scale systems for detection, monitoring, or risk management in ads, payments, or related domains.
• 3+ years of experience designing and deploying fraud detection or anomaly detection models, user behavior modeling, or risk scoring systems.
• Significant experience in one or more general-purpose programming languages like Python, Go, Scala, C++ or similar.
• Knowledge of metric design, experimentation methodologies, and large-scale data analysis.

• 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.

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.

• Guide the architecture and low level design of distributed systems to ensure scalability, reliability, and efficiency
• Own and operate infrastructure services with the engineering teams, including on call responsibilities and deep debugging of complex issues
• Drive operational excellence through improved observability, resiliency, and automation
• Mentor engineers and raise the technical bar through design reviews, code reviews, and engineering best practices
• Advise leadership on platform direction, long term investment, and adoption of emerging infrastructure technologies

• 7 or more years of experience building and operating large scale distributed systems in production
• Programming experience for backend service and infrastructure development
• Hands on experience with Kubernetes and cloud native systems in GCP, AWS, or Azure
• Expertise in distributed infrastructure including traffic management, load balancing, networking, and large scale data processing.
• Deep understanding of networking, observability, and debugging distributed systems end to end

• Deep expertise in distributed caching or storage systems used to support large scale, low latency workloads
• Expertise in protocols, routing, and service discovery in large scale environments
• Domain knowledge of online advertising and adtech systems is a plus

• Relocation support is not available for this position
• Work visa/immigration sponsorship is not available for this position

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.

As part of the team, you will work on distributed systems that handle real-time ad requests, impression tracking, and user data analytics with strict requirements for uptime and security. You'll play a critical role in optimizing performance, maintaining service availability, and supporting the development of new monetization features for game developers worldwide. Security, data privacy, and a positive user experience are central to everything we build.

• Design, build, and modernise backend services and APIs that support ad delivery
• Work on scalable, high-availability systems used across Unity’s ads ecosystem
• Collaborate with engineers, product managers, and data teams to deliver new features
• Improve performance, observability, and cost-efficiency of current backend systems, modernising the legacy stack
• Contribute to architectural decisions and technical direction of the platform

• Experience building backend services at scale
• Proficiency in Golang, and relational databases (e.g., MySQL)
• Familiarity with cloud infrastructure and observability tools (Kubernetes, Ray, etc.)
• Understanding of API design, distributed systems, and system reliability
• Strong collaboration and communication skills in a remote-first team environment

• Experience in ad tech, programmatic advertising, or real-time bidding systems
• Background with infrastructure-as-code (e.g., Terraform)
• Familiarity with networking, caching, or real-time data pipelines

• Relocation support is not available for this position.
• Work visa/immigration sponsorship is not available for this position

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 .

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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.

• Design, implement, and maintain high-performance CTR and CVR prediction models that power ad ranking and recommendation systems.
• Build and refine systems for creative understanding and user behavior modeling, enabling more accurate and context-aware engagement predictions.
• Ensure model quality and reliability by continuously monitoring performance, calibrating predictions, and addressing data drift or delayed feedback.
• 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.

• Advanced degree (MS or Ph.D.) in Computer Science, Machine Learning, Statistics, 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 CTR/CVR systems, content understanding, or behavior modeling systems.
• Significant experience in one or more general-purpose programming languages like Python, Go, Scala, C++ or similar.
• Knowledge of metric design, experimentation methodologies, and large-scale data analysis.

• 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.

• International relocation support is not available for this position.

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.

You will be responsible for driving ad unit innovation — from dynamic rendering and interactive endcards to new ad flows that elevate user experience and improve monetization outcomes.

This role combines hands-on technical design with strategic leadership. You’ll work across Android, iOS, WebView, and backend services to build, experiment, and scale ad formats that reach billions of devices globally.

• Lead the design and implementation of innovative ad unit formats and flows — including dynamic rendering, interactive components, and seamless inline ad experiences.
• Prototype and experiment rapidly, collaborating with PMs, BIs, and Data Science to validate hypotheses and measure impact through A/B testing.
• Architect and deliver full-stack solutions, connecting SDK surfaces with backend ad delivery and configuration services.
• Drive the ad format innovation roadmap — identify opportunities, define technical direction, and quantify business impact.
• Mentor engineers across Android, iOS, and WebView platforms, promoting engineering best practices and experimentation culture.
• Collaborate with backend and Gateway teams to enhance ad rendering pipelines, caching strategies, and lifecycle performance.
• Own feature metrics such as load rate, show rate, CTR, and revenue lift, ensuring performance scales post-rollout.
• Contribute to the Bold SDK architecture, helping establish a modular and extensible foundation for future ad format innovations.

• 8+ years of software engineering experience, with a focus on mobile SDKs, rendering frameworks, or ad delivery systems.
• Expertise in front-end technologies: JavaScript/TypeScript, HTML/CSS, and hybrid rendering using WebView.
• Full-stack proficiency — ability to design APIs and data flows that connect mobile clients to backend services.
• Demonstrated success in leading experimentation-driven development, including feature flagging, rollout, and monitoring.
• Strong understanding of mobile ad lifecycle, caching, rendering, and performance optimization.
• Proven ability to influence cross-functional partners and align engineering, product, and data science teams around shared goals.
• Excellent communication and technical leadership skills, capable of driving both architectural vision and hands-on delivery.

• Background in ad tech (VAST, MRAID, SKOverlay, SKAdNetwork, IAP, attribution).
• Experience with SDK, Gateway, or other large-scale delivery ecosystems.
• Familiarity with dynamic UI rendering frameworks or runtime layout generation.
• Experience working with experimentation platforms, telemetry pipelines, or BI data tooling.

• Relocation support is not available for this position
• Work visa/immigration sponsorship is not available for this position

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.

• Design, build, and evolve backend services, libraries, and frameworks that form the foundation of Unity's data platform
• Define and own APIs and developer facing tools that improve how teams ingest, process, and use data
• Lead design reviews, architectural discussions, and technical planning, ensuring the platform is reliable, extensible, and future ready
• Mentor engineers across the team, raising the bar for code quality, testing, and software craftsmanship
• Collaborate with product, ML, and data engineering teams to translate requirements into scalable platform features

• 8 or more years of software engineering experience with strong proficiency in Java and backend development
• Proven track record of designing and delivering large scale software systems or frameworks used by multiple teams
• Expertise in building and maintaining APIs, ideally with gRPC, REST, and schema technologies such as Protobuf or Avro
• Strong knowledge of distributed systems and event driven architectures
• Ability to drive cross team initiatives, align stakeholders, and make pragmatic tradeoffs that balance scale, performance, and developer experience

• Experience with streaming frameworks such as Apache Flink and Spark
• Background in building SDKs, developer platforms, or internal frameworks adopted across organizations
• Familiarity with large scale data platform challenges such as ingestion, enrichment, and schema management

• Relocation support is not available for this position
• Work visa/immigration sponsorship is not available for this position

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.

• Design, implement, and scale AI agents that assist in generating game code and executing goal-directed behaviors.
• Define orchestration logic for single- and multi-agent systems
• Develop reusable agentic frameworks - planning modules, memory systems, or policy adaptation layers - for creator extensibility.
• Lead high-impact initiatives, including hierarchical reinforcement learning for scalable behaviors, AI planning and goal inference frameworks for NPCs and simulations, and agent memory and world modeling systems for persistent, believable behavior.
• Collaborate across internal and external teams to unlock innovative use cases in gaming, simulation, and interactive storytelling.
• Contribute to the long-term vision and roadmap for Unity’s agentic AI offerings, ensuring modularity, usability, and performance across platforms.
• Establish and champion best practices for model quality, simulation-based evaluation, and ML/AI safety within real-time systems.

• Advanced degree (MS or Ph.D.) in Computer Science, Machine Learning, or a related field.
• 5+ years of hands-on experience developing ML systems in production, ideally within real-time or interactive environments.
• Experience with multi-agent systems, orchestration, or AI tool integration.
• Strong background in one or more of the following: LLM, reinforcement learning, decision-making under uncertainty, AI planning, or multi-agent systems.
• Proficiency in at least one general-purpose programming language (e.g., Python, C++, Go, Java) and familiarity with ML frameworks (e.g., PyTorch, TensorFlow).
• Strong system design skills and the ability to architect performant, scalable ML systems.
• Excellent communication and collaboration skills; ability to work effectively with cross-functional teams including engine developers, designers, and product managers.

• Familiarity with game development workflows.
• Publications or open-source contributions in reinforcement learning, agent-based modeling, or related areas.
• Experience with behavior trees, utility AI, or hierarchical task planning.
• Passion for the gaming industry and AI applications in games.

• Relocation support is not available for this position.

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.