Member of Technical Staff - Model Training

At Inflection AI, our public benefit mission is to harness the power of AI to improve human well-being and productivity.

The next era of AI will be defined by agents we trust to act on our behalf.

We're pioneering this future with human-centered AI models that unite emotional intelligence (EQ) and raw intelligence (IQ)-transforming interactions from transactional to relational, to create enduring value for individuals and enterprises alike.

Our work comes to life in two ways today:

Pi, your personal AI, designed to be a kind and supportive companion that elevates everyday life with practical assistance and perspectives.

Platform - large-language models (LLMs) and APIs that enable builders, agents, and enterprises to bring Pi-class emotional intelligence into experiences where empathy and human understanding matter most.

We are building toward a future of AI agents that earn trust, deepen understanding, and create aligned, long-term value for all.

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, Deep Speed) 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/Deep Speed, 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