LLM Modeling & Post-Training Engineer

Location: Calumet

LLM Modeling & Post-Training Engineer

About the Opportunity

We're partnering with a globally recognized enterprise organization that is making a significant investment in next-generation AI capabilities and building a world-class AI Engineering function.

This team is focused on developing advanced AI systems that combine frontier AI research with large-scale enterprise deployment, tackling some of the most challenging problems in reasoning, alignment, reliability, safety, and model optimization.

As an LLM Modeling & Post-Training Engineer, you'll play a key role in shaping the behavior, performance, and reliability of large language models used across complex, high-impact environments. Working alongside AI researchers, platform engineers, architects, and product leaders, you'll help bridge the gap between cutting-edge AI research and production-grade systems operating at scale.

This role focuses on the core modeling layer of modern AI systems - supervised fine-tuning, reinforcement learning, preference optimization, reward modeling, alignment, evaluation, and large-scale training workflows.

We are looking for individuals who understand not only how to use LLMs, but how to improve and shape model behavior through advanced post-training techniques.

This is not a prompt-engineering-only role. The ideal candidate has hands-on experience with fine-tuning and aligning open-weight or proprietary foundation models using techniques such as SFT, RLHF, PPO, DPO, GRPO, RLAIF, LoRA, and QLoRA, and understands how these methods impact reasoning quality, safety, latency, cost, and production reliability.

Work You'll Do

As an LLM Modeling & Post-Training Engineer, you will design, train, evaluate, and optimize large language models for enterprise use cases involving complex reasoning, domain specialization, structured outputs, workflow execution, and alignment with business objectives.

You will work across the full post-training lifecycle, including:

Supervised fine-tuning (SFT)
Reinforcement learning and alignment
Preference optimization and reward modeling
Synthetic data generation and curation
Evaluation and benchmarking
Model safety and red teaming
Distributed training and inference optimization
Productionization of fine-tuned models

You will collaborate with platform engineers, domain experts, AI architects, and product leaders to translate complex business requirements into high-performing, reliable, and controllable AI systems.

The Team

You will join a multidisciplinary team of AI researchers, modeling engineers, platform engineers, architects, and domain specialists building next-generation enterprise AI systems.

The team operates at the intersection of frontier AI research and large-scale enterprise engineering, tackling highly complex reasoning challenges, evolving operational workflows, and demanding reliability requirements.

Success in this role requires strong technical depth, intellectual curiosity, an experimentation mindset, and the ability to translate advanced AI research into practical, production-ready systems.

Why Apply?

Work on cutting-edge AI challenges involving reasoning, alignment, and post-training
Help shape the next generation of enterprise AI systems
Collaborate with highly technical researchers, engineers, and architects
Access modern AI infrastructure, tooling, and large-scale training environments
Join a growing AI organization with significant executive sponsorship and long-term investment
Competitive compensation and strong career growth opportunities