Our team is responsible for the core systems that power Microsoft 365 Copilot Chat delivering intelligence, quality, and transformative new features. We work at the intersection of research and engineering—advancing orchestrator reasoning, training next-generation models, and shipping impactful, model-driven experiences in Microsoft 365 Copilot.
As a Principal Applied Scientist, you will:

• Evolve our orchestrator to reason more effectively, respond faster, and support new capabilities in multi-modality, agent-based systems, and beyond
• Advance the state of the art in model training—including post-training methods such as fine-tuning and reinforcement learning, high-quality data curation, and experimentation with frontier model training
• Build and deliver model-driven features from concept to production—spanning model development, evaluation, metrics, and A/B testing

Recent launches like Analyst Agent in Microsoft 365 Copilot showcase the breadth and depth of impact you’ll drive across the stack.
We’re hiring applied scientists who are passionate about deep learning, NLP (natural language processing), multimodality model, and model optimization. Come build the next generation of AI with us.
Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.