AI Engineer

Liminary (Headquarters: Seattle, Bay Area or NYC)

AI ML LLM RAG Semantic Search PyTorch TensorFlow LangChain LlamaIndex Founding Team NLP Python Transformers Fine-tuning Reinforcement Learning AI Engineer Data Science

Liminary is building the future of knowledge work. We believe in a future where AI amplifies human potential, enabling people everywhere to solve their own challenges in powerful new ways. We're building that future today and looking for exceptional people who share our vision and are excited to grow with us. Liminary is building a cognitive companion for knowledge workers that fundamentally transforms how people work with information. In a world drowning in scattered information and AI-generated content, we're creating an ambient AI that works alongside you, seamlessly saving and surfacing the right knowledge exactly when you need it.

About the Role:
We're looking for an AI/ML Engineer to help build and lead the development of our cognitive companion for knowledge workers. In this founding role, you'll shape our AI strategy and technical foundation, working with large language models, retrieval systems, and human-AI interaction patterns. You'll have the opportunity to fine-tune models and integrate cutting-edge AI capabilities to create something truly innovative. Your work will directly transform how people think, work, and manage their information in ways that haven't been possible before.

You would enjoy being a member of our team if you:
* Are happiest when building something meaningful from the ground up
* Love working in a fast-paced, collaborative startup (or 0→1) environment
* Bring strong well-informed opinions about technical excellence and user impact
* Bring interdisciplinary thinking to your work, drawing from interests beyond technology to inform our approach to human-AI interaction
* Value user trust, privacy, and security as core tenants of product development
* Are energized by exploring the possibilities at the intersection of AI systems and human cognition

In this role, you will:
* Architect and lead the development of our predictive intelligence system built on foundation models, focusing on RAG, semantic search, personalized content orchestration, and reinforcement learning
* Drive innovation by engaging with and evaluating the latest developments in machine learning and AI
* Design and implement scalable data pipelines, optimizing models for performance, accuracy, and production-readiness
* Lead technical evaluation of new AI/ML approaches and foundation models and make strategic decisions about technology adoption
* Design and execute experiments to measure model performance, user engagement, and system effectiveness
* Monitor and maintain production ML systems, ensuring consistent performance and value delivery
* Foster a culture of technical excellence and continuous learning by mentoring team members, championing best practices, and helping establish the engineering values that will shape our company's future

Your background looks something like:
Required:
* Master's/PhD degree in Computer Science, Machine Learning, or a related field
* Extensive proven experience building and maintaining production machine learning systems
* Expertise in transformer architectures and practical experience with foundation models
* Strong proficiency in PyTorch, TensorFlow
* Demonstrated experience with LLM fine-tuning methods, like distillation, supervised fine-tuning, and reinforcement learning
* Hands-on experience with LLM orchestration tools (LangChain, LlamaIndex) and major foundation model APIs
* Proven ability to architect high-performance, large-scale ML systems

Bonus:
* Research experience in generative AI, particularly in areas relevant to retrieval, multimodal understanding, and human thinking.
* Contributions to open-source ML projects or development of novel ML techniques
* Experience with distributed systems and large-scale data processing
* Background in cognitive science, information retrieval, or human-computer interaction

Note: You must have work authorization in the United States for this role. We are not able to provide any immigration support at this time.