Member of Technical Staff – Model Training

About the Role

As a Model Training engineer, you will design, build, and scale the post-training pipelines that turn a general LLM into a brand-fluent, production-ready assistant. Your innovations in fine-tuning and preference optimization (RLHF, DPO, GRPO, RLAIF) will directly improve reliability, alignment, and cost.

This is a good role for you if you:

• Have hands-on experience training and fine-tuning large transformer models on multi-GPU / multi-node clusters.
• Are fluent in PyTorch and its ecosystem tools (Torchtune, FSDP, DeepSpeed) and enjoy digging into distributed-training internals, mixed precision, and memory-efficiency tricks.
• Have shipped or published work in RLHF, DPO, GRPO, or RLAIF and understand their practical trade-offs.
• Care deeply about training tools, pipelines, and reproducibility—you automate the boring parts so you can iterate on the fun parts.
• Balance research curiosity with product pragmatism—you know when to run an ablation and when to ship.
• Communicate crisply with both technical and non-technical teammates.
• Have a bachelor’s degree or equivalent in a related field to the offered position requirements.

Responsibilities include:

• Contribute to end-to-end post-training workflows—dataset curation, hyper-parameter search, evaluation, and rollout—using PyTorch, Torchtune, FSDP/DeepSpeed, and our internal orchestration stack.
• Prototype and compare alignment techniques (e.g., curriculum RL, multi-objective reward modeling, tool-use fine-tuning) and push the best ideas into production.
• Automate training at scale: build robust pipeline components, tools, scripts, and dashboards so experiments are reproducible and easy to trace.
• Define the metrics that matter; run A/B tests and iterate quickly to meet aggressive quality targets.
• Collaborate with inference, safety, and product teams to land improvements in customer-facing systems.

Employee Pay Disclosures

At Inflection AI, we aim to attract and retain the best employees and compensate them in a way that appropriately and fairly values their individual contributions to the company. For this role, Inflection AI estimates a starting annual base salary to fall within the range of $175,000 to $350,000, depending on a candidate’s qualifications and level of experience. This role also includes a meaningful equity component, allowing employees to share in the long-term success of the company.

Benefits

Inflection AI values and supports our team’s mental and physical health. We are focused on building a positive, safe, inclusive and inspiring place to work. Our benefits include: 

• Diverse medical, dental and vision options 
• 401k matching program 
• Unlimited paid time off 
• Parental leave and flexibility for all parents and caregivers
• Support of country-specific visa needs for international employees living in the Bay Area