Research Engineer, Post-Training Inference
Together AI
Research Engineer, Post-Training Inference at Together AI is a full time role based in San Francisco, California, United States. It was published on 6 July 2026 and was open at last check.
| Role | Research Engineer, Post-Training Inference |
|---|---|
| Company | Together AI |
| Location | San Francisco, California, United States |
| Employment type | Full Time |
| Published | 6 July 2026 |
| Status | Open at last check |
About the role
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.
As a Research Engineer within Model Shaping, you will develop a platform that enables users to customize open-source models with their own data. Working across the training and inference stacks, you will build and improve our Fine-Tuning, Reinforcement Learning, and Evaluation services – from ensuring a seamless path from post-training to production serving, to optimizing the inference engine for RL training workloads. You will collaborate closely with our product, research, and engineering teams to keep the API reliable, performant, and well integrated into the company's technical infrastructure. Above all, you will help build the foundational layer of the open-source AI ecosystem, enabling developers around the world to efficiently create high-quality models tailored to their specific applications.
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
Requirements
- 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
Experience in any of the following will make you stand out
- 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
About Together AI
Together AI is a research-driven artificial intelligence company. We believe open and transparent AI systems will drive innovation and create the best outcomes for society, and together we are on a mission to significantly lower the cost of modern AI systems by co-designing software, hardware, algorithms, and models. We have contributed to leading open-source research, models, and datasets to advance the frontier of AI, and our team has been behind technological advancement such as FlashAttention, ATLAS, RedPajama, and Mamba. We invite you to join a passionate group of researchers in our journey in building the next generation AI infrastructure.
Compensation
We offer competitive compensation, startup equity, health insurance, and other benefits. The US base salary range for this full-time position is $200,000 - $290,000. Our salary ranges are determined by location, level and role. Individual compensation will be determined by experience, skills, and job-related knowledge.
Equal Opportunity
Together AI is an Equal Opportunity Employer and is proud to offer equal employment opportunity to everyone regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, veteran status, and more.
Please see our privacy policy at https://www.together.ai/privacy
Create your free OnJob profile to apply — we'll take you to Together AI's application after sign-up. · Posted 6 Jul 2026.
Research Engineer, Post-Training Inference at Together AI — questions answered
What does the Research Engineer, Post-Training Inference role at Together AI pay?
Together AI does not publish a salary on this Research Engineer, Post-Training Inference listing, so OnJob shows no figure for it rather than an estimate. For what this role pays across the market, the OnJob salary guides aggregate the live listings that do disclose pay.
Where is the Research Engineer, Post-Training Inference role at Together AI based?
Together AI lists this Research Engineer, Post-Training Inference role in San Francisco, California, United States, advertised as full time work at that location. Larger employers sometimes cover several sites under one city name, so confirm the exact office with Together AI before you apply.
Is the Research Engineer, Post-Training Inference role at Together AI still open?
The Research Engineer, Post-Training Inference posting at Together AI was open at OnJob's last check of the employer's careers page, having been published on 6 July 2026. OnJob re-checks source listings on each build and marks a role closed once it disappears, but listings can close without notice, so the employer's own page is the final word.
How do you apply for the Research Engineer, Post-Training Inference role at Together AI?
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