Microsoft / CodeAI
Senior Research Scientist
Aug 2026 – Present
Research Scientist II
Mar 2026 – Jul 2026
- Built a reinforcement learning environment combining a coding-agent harness and user simulator to generate multi-turn rollouts and rewards. Trained small coordinator LLMs to compose tool-using workflows and route steps across models for GitHub Copilot Fusion.
- At its max setting in Copilot CLI, the released system performed within approximately two index points of Claude Code with Opus 5.5 (max), at 51% lower API cost per task, on the Artificial Analysis Coding Agent Index v2.0 (October 2026).
- Led development of a fine-tuned ModernBERT credential scanner deployed at the scale of all GitHub push traffic. Improved precision over multi-LLM workflows by over 11.5% in online A/B tests, while reducing inference cost by over 98% and latency by over 86%. GitHub blog.
Applied Scientist II
May 2024 – Feb 2026
- Co-developed multilingual training for GPT-4o across mid-training, SFT, DPO, and RLHF; built large-scale benchmarks, scalable evaluation pipelines, and synthetic-data generation systems.
- Developed calibrated confidence estimation using auxiliary predictors and RL-based post-training with calibrated rewards, improving hallucination detection by 10% AUROC in production systems, including vision-language models for structured extraction from long documents.
- Designed tool-calling, retrieval, and search workflows for Azure AI Foundry Agents and improved response latency by 30% without reducing quality.