[2026] Senior Machine Learning Engineer, Natural Language Processing PhD Early Career

Natural Language Processing (NLP) is central to enabling massive-scale communication creation and safety across the Roblox platform. This role offers the unique opportunity to build and deploy cutting-edge NLP speech and generative AI models that operate at an unprecedented scale impacting hundreds of millions of daily users.

You will solve an extremely diverse range of high-scale language-related problemsfrom real-time moderation of voice and text to automatically localizing experiences and empowering users through LLM-driven creation tools . We combine cutting-edge research with large-scale engineering to bridge experimentation and production designing algorithms that shape the next generation of language services for our immersive user-generated content platform.

Teams Hiring for This Role

• Safety AI Systems: Dedicated to building end-to-end ML systems for maintaining civility and safety across the platform operating at massive scale. This includes:
  • Real-time Moderation: Building world-class NLP and speech models for real-time moderation of voice and text (processing over 6 billion messages daily) and advanced interventions that measurably improve user civility.
  • Critical Harms & Advanced Detection: Developing specialized LLM agents behavioral analysis and graph systems for detecting and preventing rare high-risk scenarios (e.g. child safety terrorism) requiring adversarial thinking and multi-step reasoning.
  • Safety Data Quality: Ensuring all Safety AI systems are robust by managing the core data infrastructure MLOps and Active Learning initiatives for continuous model improvement.

You Will

• Design and implement deep learning-based NLP and speech solutions that address problems across Roblox from creation to safety.
• Develop advanced models including Large Language Models (LLMs) machine translation and generative AI for user interactions content creation and moderation.
• Have the independence and end-to-end responsibility to develop NLP/ML-based services that are scalable and resilient.
• Be a technical bar-raiser for cutting-edge ML technology high code quality and architectural designs.
• Work backward from user and product needs to deliver ML solutions that drive engagement safety and ecosystem growth.

You Have

• Possessing or pursuing a Ph.D. in Computer Science Computer Engineering Mathematics Statistics or a related technical field with a thesis aligned to Robloxs research areas.
• Expertise in one or more areas: NLP Speech Models Large Language Models Machine Translation or Generative AI (including diffusion models).
• Experience with transformer-based model design training serving and product integration.
• A strong research track record evidenced by multiple publications and presentations in top-tier peer-reviewed venues (e.g. ACL EMNLP Interspeech ICML NeurIPS).
• Proficiency in one or more programming languages (e.g. Python C Go Java) and experience building and optimizing large-scale systems.

You may redact age date of birth and dates of attendance/graduation from your resume if you prefer.

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Required Experience:

Senior IC