Research Engineer, Post-Training Inference

Together AI
San Francisco / San Francisco, San Francisco, California, United States2026-07-06

About the job

The Model Shaping team at Together AI works on products and research focused on tailoring open foundation models to downstream applications. We build services that enable machine learning developers to choose the best models for their tasks and further improve these models using domain-specific data. In addition, we develop new methods for more efficient model training and evaluation, drawing inspiration from a broad range of ideas across machine learning, natural language processing, and ML systems.

Responsibilities

Design and build Together’s systems for customizing open-source models

Build integrations between the Model Shaping and Inference platforms to ensure a seamless path from post-training to serving production workloads

Add features to inference engines for large-scale post-training experiments, including optimizations for RL workloads

Make sure the service is stable and robust, participating in an on-call rotation and ensuring 24/7 availability of our platform

Qualifications

Minimum

Have 2+ years of experience building and deploying machine learning-based services in a production environment

Have hands-on experience with modern inference engines, such as SGLang, vLLM, and TensorRT-LLM

Are familiar with the latest methods for fine-tuning LLMs and other AI models

Have a strong software engineering background in Python or Go

Stay up to date with the latest advances and trends in the machine learning community

Preferred

Serving low-precision (FP4/FP8) models, multiple LoRA adapters within one model instance (Multi-LoRA), or models distributed across several GPU nodes

Optimizing the performance of RL training workloads

Developing CUDA/Triton/CuTE DSL kernels for inference

Developing large-scale and high-load production systems

Maintaining or contributing to open-source ML projects

Managing machine learning workloads on Kubernetes clusters