Research Engineer, Post-training Inference

Together AI Together AI · Data AI · San Francisco, CA · Research

Research Engineer focused on customizing open-source foundation models for downstream applications. The role involves building and improving services for fine-tuning, reinforcement learning, and evaluation, with a strong emphasis on integrating post-training processes with production serving and optimizing inference for RL training workloads. Requires experience in building and deploying ML services, modern inference engines, and fine-tuning techniques.

What you'd actually do

  1. Design and build Together’s systems for customizing open-source models
  2. Build integrations between the Model Shaping and Inference platforms to ensure a seamless path from post-training to serving production workloads
  3. Add features to inference engines for large-scale post-training experiments, including optimizations for RL workloads
  4. Make sure the service is stable and robust, participating in an on-call rotation and ensuring 24/7 availability of our platform

Skills

Required

  • 2+ years of experience building and deploying machine learning-based services in a production environment
  • hands-on experience with modern inference engines, such as SGLang, vLLM, and TensorRT-LLM
  • familiarity with the latest methods for fine-tuning LLMs and other AI models
  • strong software engineering background in Python or Go
  • stay up to date with the latest advances and trends in the machine learning community

Nice to have

  • Serving low-precision (FP4/FP8) models
  • multiple LoRA adapters within one model instance (Multi-LoRA)
  • 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

What the JD emphasized

  • modern inference engines
  • fine-tuning LLMs
  • RL training workloads

Other signals

  • customizing open-source models
  • fine-tuning
  • reinforcement learning
  • evaluation services
  • inference optimization