Yiwen Xiang

About Yiwen Xiang

Machine Learning Engineer focused on large language models and production ML systems. Experienced in LLM post-training, including RLHF and SFT frameworks, and policy optimization approaches such as ARPG and GRPO. I also work on hallucination control and improving reliability and grounded behavior in LLM outputs. Previously contributed to large-scale recommender systems, including Reels ranking at Meta.

Experience

1. Software Engineer Machine Learning

   Meta

   Jan 2025 — Present · Menlo Park, CA, US

   Monetization GenAI- LLM post training (Reinforcement learning or SFT), LLM hallucination control, RAG.

Education

• University of Illinois Urbana-Champaign

  Master of Science (MS), Agronomy and Crop Science

  2010 — 2013

• The Data Incubator

  Data Science

  2017 — 2017

• University of Illinois Urbana-Champaign

  Master’s Degree, Statistics

  2014 — 2016

• University of Illinois Urbana-Champaign

  Doctor of Philosophy (Ph.D.), Plant Pathology/Phytopathology

  2013 — 2017

• Michigan State University

  Bachelor of Science, Crop and Soil Sciences

  2005 — 2010

Skills

• Hadoop
• Mycology
• Experimental Design
• Microsoft Office
• Genetics
• R
• Gel Electrophoresis
• Plant Breeding
• Environmental Engineering
• Jmp
• Agribusiness
• Environmental Microbiology
• Gis
• Python
• Data Analysis
• Laboratory
• Artificial Neural Networks
• Plant Identification
• Soil Sampling
• Bioinformatics
• Pcr
• Sql
• Molecular Biology
• Fluorescence Microscopy
• Machine Learning
• Agronomy
• Microbiology
• Sas
• Dna Extraction
• Research Design
• Microscopy
• Turf
• Statistics
• Agriculture
• R&D
• Environmental Awareness
• Plant Pathology
• Chemistry
• Environmental Science
• Landscape Architecture