Lukas Xue

Lukas (Renhao) Xue

ML Research Engineer — LLM Post-Training, Alignment & Inference
AWS Generative AI Innovation Center · B.S. in CS @ Emory University

About

I work across the full model customization stack — from RLHF and reward modeling to efficient serving — with a strong interest in mechanistic interpretability. I build production systems for training and deploying models at tens-to-hundreds of billions of parameters, and publish at top venues including ICML.

Experience

Feb 2023 – Present
Machine Learning Engineer
Amazon Web Services
Progressed through multiple AWS AI/ML teams. Promoted to SDE II in April 2025.
May 2025 – Present
MLE · Custom Model Optimization (CMO)
AWS Generative AI Innovation Center
Leading R&D in LLM post-training — CPT, SFT, and Reinforcement Learning (GRPO, DPO) — for models at tens-to-hundreds of billions of parameters (Nova, Qwen families). Training infrastructure with FSDP, DDP, HuggingFace, and Lightning on SageMaker HyperPods. Production inference with vLLM, Triton Inference Server, TensorRT, ONNX Runtime, and HuggingFace TEI on EKS and SageMaker endpoints. Also driving prompt optimization and model steering research.
Aug 2024 – May 2025
SDE → SDE II · Bedrock Model Customization
Led development of Supervised Fine-Tuning for LLMs (Llama 3 family) in Amazon Bedrock. Re-architected custom model inference from merged adapters on provisioned throughput to adapter hotloading on base model capacity — enabling efficient multi-tenant serving without dedicated compute per adapter.
Apr 2024 – Aug 2024
SDE · SageMaker AutoPilot & Canvas
AutoML for tabular data, time-series forecasting, and language model fine-tuning. Helped make ML accessible to non-practitioners through Canvas's no-code interface.
Feb 2023 – Apr 2024
SDE · Managed Streaming for Apache Kafka (MSK)
Kafka on AWS Graviton chips and MSK Express Brokers with a fully managed storage layer. Optimized performance and cost for real-time streaming workloads at scale.
May 2022 – Aug 2022
SDE Intern, MSK
Amazon Web Services
Built real-time fault-tolerant data pipelines and streaming infrastructure. First exposure to distributed systems at AWS scale.
Summer 2021
Full Stack Intern
A.P. Moller – Maersk
Modernized Maersk's shipping logistics platform. Built features for container tracking and shipment management across global supply chain operations.

Education

M.S. Information Studies
Trine University
Aug 2025 – Present · Part-time
GPA: 4.0/4.0. Focus on data systems, information architecture, and applied research.
B.S. Computer Science
Emory University
2021 – Dec 2022
Minor in Applied Mathematics. GPA: 3.938/4.000. Coursework in algorithms, systems, ML, and mathematical foundations.
Student Researcher — Data mining and graph neural networks.
Teaching Assistant — CS334 Machine Learning, CS326 Analysis of Algorithms.
Associate of Arts
Oxford College of Emory University
2019 – 2021
Liberal arts foundation before transitioning to Atlanta for upper-division CS coursework.

Publications

* Equal contribution

Projects

Certifications

AWS AI Foundational
AWS AI Foundational (L100)
Dec 2025
AWS AI Practitioner
AWS Certified AI Practitioner
Aug 2025
AWS ML Engineer
AWS Certified ML Engineer – Associate
May 2025
AWS ML Specialty
AWS Certified ML – Specialty
Apr 2023
AWS Developer Associate
AWS Certified Developer – Associate
May 2022